tdef: Introduce OSMO_TDEF_US unit

Some applications may need submillisecond timers, such as those
interacting with modbus serial lines (RS-485, RTU), which require
timers of values around 1.5 char-time (T1.5), where a data char is
composed of 11 bits sent on the line: 1 start bit, 8 data bits,
1 stop bit, and and parity bit (or 2nd stop bits if no parity).

For instance, for a baudrate of 9600:
1.5 * 11 / 9600 = 1.718 ms = 1718 us

So having a granularity of MS is not enough here.

Change-Id: I71848d7c1ee0649929ce07680ee7320bb2a42f0e
diff --git a/tests/tdef/tdef_test.ok b/tests/tdef/tdef_test.ok
index 3c4a093..1770968 100644
--- a/tests/tdef/tdef_test.ok
+++ b/tests/tdef/tdef_test.ok
@@ -5,92 +5,116 @@
 osmo_tdef_get(1, ms)	= 100000
 osmo_tdef_get(1, m)	= 2
 osmo_tdef_get(1, custom-unit)	= 100
+osmo_tdef_get(1, us)	= 100000000
 T2=100ms
 osmo_tdef_get(2, s)	= 1
 osmo_tdef_get(2, ms)	= 100
 osmo_tdef_get(2, m)	= 1
 osmo_tdef_get(2, custom-unit)	= 100
+osmo_tdef_get(2, us)	= 100000
 T3=100m
 osmo_tdef_get(3, s)	= 6000
 osmo_tdef_get(3, ms)	= 6000000
 osmo_tdef_get(3, m)	= 100
 osmo_tdef_get(3, custom-unit)	= 100
+osmo_tdef_get(3, us)	= 6000000000
 T4=100custom-unit
 osmo_tdef_get(4, s)	= 100
 osmo_tdef_get(4, ms)	= 100
 osmo_tdef_get(4, m)	= 100
 osmo_tdef_get(4, custom-unit)	= 100
+osmo_tdef_get(4, us)	= 100
 T7=50s
 osmo_tdef_get(7, s)	= 50
 osmo_tdef_get(7, ms)	= 50000
 osmo_tdef_get(7, m)	= 1
 osmo_tdef_get(7, custom-unit)	= 50
+osmo_tdef_get(7, us)	= 50000000
 T8=300s
 osmo_tdef_get(8, s)	= 300
 osmo_tdef_get(8, ms)	= 300000
 osmo_tdef_get(8, m)	= 5
 osmo_tdef_get(8, custom-unit)	= 300
+osmo_tdef_get(8, us)	= 300000000
 T9=5m
 osmo_tdef_get(9, s)	= 300
 osmo_tdef_get(9, ms)	= 300000
 osmo_tdef_get(9, m)	= 5
 osmo_tdef_get(9, custom-unit)	= 5
+osmo_tdef_get(9, us)	= 300000000
 T10=20m
 osmo_tdef_get(10, s)	= 1200
 osmo_tdef_get(10, ms)	= 1200000
 osmo_tdef_get(10, m)	= 20
 osmo_tdef_get(10, custom-unit)	= 20
+osmo_tdef_get(10, us)	= 1200000000
 T1000=2000ms
 osmo_tdef_get(1000, s)	= 2
 osmo_tdef_get(1000, ms)	= 2000
 osmo_tdef_get(1000, m)	= 1
 osmo_tdef_get(1000, custom-unit)	= 2000
+osmo_tdef_get(1000, us)	= 2000000
 T1001=60000ms
 osmo_tdef_get(1001, s)	= 60
 osmo_tdef_get(1001, ms)	= 60000
 osmo_tdef_get(1001, m)	= 1
 osmo_tdef_get(1001, custom-unit)	= 60000
+osmo_tdef_get(1001, us)	= 60000000
 T1004=1ms
 osmo_tdef_get(1004, s)	= 1
 osmo_tdef_get(1004, ms)	= 1
 osmo_tdef_get(1004, m)	= 1
 osmo_tdef_get(1004, custom-unit)	= 1
+osmo_tdef_get(1004, us)	= 1000
 T1005=0ms
 osmo_tdef_get(1005, s)	= 0
 osmo_tdef_get(1005, ms)	= 0
 osmo_tdef_get(1005, m)	= 0
 osmo_tdef_get(1005, custom-unit)	= 0
+osmo_tdef_get(1005, us)	= 0
 T1006=0s
 osmo_tdef_get(1006, s)	= 0
 osmo_tdef_get(1006, ms)	= 0
 osmo_tdef_get(1006, m)	= 0
 osmo_tdef_get(1006, custom-unit)	= 0
+osmo_tdef_get(1006, us)	= 0
 T1007=0m
 osmo_tdef_get(1007, s)	= 0
 osmo_tdef_get(1007, ms)	= 0
 osmo_tdef_get(1007, m)	= 0
 osmo_tdef_get(1007, custom-unit)	= 0
+osmo_tdef_get(1007, us)	= 0
 T1008=0custom-unit
 osmo_tdef_get(1008, s)	= 0
 osmo_tdef_get(1008, ms)	= 0
 osmo_tdef_get(1008, m)	= 0
 osmo_tdef_get(1008, custom-unit)	= 0
+osmo_tdef_get(1008, us)	= 0
+T1009=0us
+osmo_tdef_get(1009, s)	= 0
+osmo_tdef_get(1009, ms)	= 0
+osmo_tdef_get(1009, m)	= 0
+osmo_tdef_get(1009, custom-unit)	= 0
+osmo_tdef_get(1009, us)	= 0
 T0=1custom-unit
 osmo_tdef_get(0, s)	= 1
 osmo_tdef_get(0, ms)	= 1
 osmo_tdef_get(0, m)	= 1
 osmo_tdef_get(0, custom-unit)	= 1
+osmo_tdef_get(0, us)	= 1
 T123=1s
 osmo_tdef_get(123, s)	= 1
 osmo_tdef_get(123, ms)	= 1000
 osmo_tdef_get(123, m)	= 1
 osmo_tdef_get(123, custom-unit)	= 1
+osmo_tdef_get(123, us)	= 1000000
 
 test_tdef_get_nonexisting()
 osmo_tdef_get(tdefs, 5, s, 999)	= 999
 osmo_tdef_get(tdefs, 5, ms, 999)	= 999
 osmo_tdef_get(tdefs, 5, m, 999)	= 999
 osmo_tdef_get(tdefs, 5, custom-unit, 999)	= 999
+osmo_tdef_get(tdefs, 5, us, 999)	= 999
 
 test_tdef_set_and_get()
 setting 7 = 42
@@ -99,24 +123,28 @@
 osmo_tdef_get(7, s)	= 42
 osmo_tdef_get(7, m)	= 1
 osmo_tdef_get(7, custom-unit)	= 42
+osmo_tdef_get(7, us)	= 42000000
 setting 7 = 420
 T7=420s(def=50)
 osmo_tdef_get(7, ms)	= 420000
 osmo_tdef_get(7, s)	= 420
 osmo_tdef_get(7, m)	= 7
 osmo_tdef_get(7, custom-unit)	= 420
+osmo_tdef_get(7, us)	= 420000000
 setting 7 = 10 (ERANGE)
 T7=420s(def=50)
 osmo_tdef_get(7, ms)	= 420000
 osmo_tdef_get(7, s)	= 420
 osmo_tdef_get(7, m)	= 7
 osmo_tdef_get(7, custom-unit)	= 420
+osmo_tdef_get(7, us)	= 420000000
 setting 7 = 900 (ERANGE)
 T7=420s(def=50)
 osmo_tdef_get(7, ms)	= 420000
 osmo_tdef_get(7, s)	= 420
 osmo_tdef_get(7, m)	= 7
 osmo_tdef_get(7, custom-unit)	= 420
+osmo_tdef_get(7, us)	= 420000000
 setting 23 = 50 (EEXIST)
 resetting
 T7=50s