dyn PDCH: send PDCH ACT for each TCH/F_PDCH on TS Enable

Add dyn_pdch_init() in new file bsc_dyn_pdch.c (new file to avoid linking
issues; bsc_init.c would create undefined references, and putting in a new file
is the easiest solution).

Call dyn_pdch_init() from nm_statechg_event() whenever a TS is enabled.

Revert the |= TS_F_PDCH_MODE chunk from previous commit, since this flag will
now be set after dyn_pdch_init() sent out the PDCH ACT and when subsequently
the PDCH ACT ACK messages are received in rsl_rx_pdch_act_ack().

Change-Id: I0cad93dec59d546b3f3b19e332e0833496031575
diff --git a/openbsc/src/libbsc/Makefile.am b/openbsc/src/libbsc/Makefile.am
index 8fa5c7c..48880d9 100644
--- a/openbsc/src/libbsc/Makefile.am
+++ b/openbsc/src/libbsc/Makefile.am
@@ -23,5 +23,6 @@
 			bsc_init.c bts_init.c bsc_rf_ctrl.c \
 			arfcn_range_encode.c bsc_ctrl_commands.c \
 			bsc_ctrl_lookup.c \
-			net_init.c
+			net_init.c \
+			bsc_dyn_pdch.c