introduce GSM primitive definitions

The idea here is to use the osmocom core primitive code ot abstract out
primitives for inter-layer comunication in GSM.
diff --git a/include/osmocom/gsm/Makefile.am b/include/osmocom/gsm/Makefile.am
index 547933e..aa7b1a9 100644
--- a/include/osmocom/gsm/Makefile.am
+++ b/include/osmocom/gsm/Makefile.am
@@ -1,6 +1,6 @@
 osmogsm_HEADERS = a5.h comp128.h gsm0808.h gsm48_ie.h mncc.h rxlev_stat.h \
 		  gsm0480.h gsm48.h gsm_utils.h rsl.h tlv.h abis_nm.h \
-		  sysinfo.h
+		  sysinfo.h prim.h
 
 SUBDIRS = protocol