split off osmo-sgsn: remove files, apply build

Change-Id: I5d27ff93e56cd13e0e70edd15e2080201e35e91f
diff --git a/src/gprs/gb_proxy.c b/src/gprs/gb_proxy.c
index cd38d23..d288cb3 100644
--- a/src/gprs/gb_proxy.c
+++ b/src/gprs/gb_proxy.c
@@ -47,12 +47,13 @@
 #include <openbsc/gb_proxy.h>
 
 #include <openbsc/gprs_llc.h>
-#include <openbsc/gsm_04_08.h>
 #include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
 #include <openbsc/gprs_utils.h>
 
 #include <openssl/rand.h>
 
+extern void *tall_bsc_ctx;
+
 static const struct rate_ctr_desc global_ctr_description[] = {
 	{ "inv-bvci",	    "Invalid BVC Identifier          " },
 	{ "inv-lai",	    "Invalid Location Area Identifier" },