Add mnimalistic command line interface "command.c"

This is a very simplistic command line interface parser which
various parts of the code can use to register textual commands
on the debug UART.

Change-Id: I2d289228fb97ecde5602e9756f3d7c51fa65a3b7
diff --git a/sysmoOCTSIM/gcc/Makefile b/sysmoOCTSIM/gcc/Makefile
index 1c90257..7496377 100644
--- a/sysmoOCTSIM/gcc/Makefile
+++ b/sysmoOCTSIM/gcc/Makefile
@@ -80,6 +80,7 @@
 i2c_bitbang.o \
 octsim_i2c.o \
 ncn8025.o \
+command.o \
 hpl/osc32kctrl/hpl_osc32kctrl.o \
 examples/driver_examples.o \
 driver_init.o \
@@ -126,6 +127,7 @@
 "i2c_bitbang.o" \
 "octsim_i2c.o" \
 "ncn8025.o" \
+"command.o" \
 "hpl/osc32kctrl/hpl_osc32kctrl.o" \
 "examples/driver_examples.o" \
 "driver_init.o" \
@@ -178,6 +180,7 @@
 "i2c_bitbang.d" \
 "octsim_i2c.d" \
 "ncn8025.d" \
+"command.d" \
 "examples/driver_examples.d" \
 "hal/src/hal_cache.d" \
 "hal/src/hal_sleep.d" \