lapdm: Allow user to specify T200 values; Use correct N200 values

TS 04.06 specifies a N200 re-transmission counter that depends on the
channel type, which we didn't care about at all so far.  Let's have the
caller tell us the channel type so we can internally look up the correct
N200 value for it.

At the same time, permit the user to specify T200 re-transmission timer
values for each SAPI on both DCCH and ACCH, which is required at least
in the BTS as per GSM TS 12.21.  Also, extend the timer resolution of
the API from seconds to milli-seconds, which is more applicable as
particularly on the FACCH the recommended values are in the 200ms range.

Change-Id: I90fdc4dd4720d4e02213197c894eb0a55a39158c
Related: OS#3906
Related: OS#2294
Related: OS#4037
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 9aa9683..34a1543 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -457,6 +457,7 @@
 
 lapdm_channel_exit;
 lapdm_channel_init;
+lapdm_channel_init2;
 lapdm_channel_reset;
 lapdm_channel_set_flags;
 lapdm_channel_set_l1;
@@ -465,6 +466,7 @@
 lapdm_datalink_for_sapi;
 lapdm_entity_exit;
 lapdm_entity_init;
+lapdm_entity_init2;
 lapdm_entity_reset;
 lapdm_entity_set_flags;
 lapdm_entity_set_mode;