gbproxy: Move peer definitions to gb_proxy_peer.c

This patch moves the peer related definitions from gb_proxy.c to
gb_proxy_peer.c and adjusts the prefix of each global symbol to
gbproxy_:

Peer definitions (prefix adjusted to gbproxy_):
  peer_ctr_description -> gprs/gb_proxy_peer.c (static)
  peer_ctrg_desc -> gprs/gb_proxy_peer.c (static)
  *peer_by_* -> gprs/gb_proxy_peer.c
  gbproxy_peer_alloc -> gprs/gb_proxy_peer.c
  gbproxy_peer_free -> gprs/gb_proxy_peer.c
  gbprox_cleanup_peers -> gprs/gb_proxy_peer.c

Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/Makefile.am b/openbsc/src/gprs/Makefile.am
index 4d0c9cd..a8de0a4 100644
--- a/openbsc/src/gprs/Makefile.am
+++ b/openbsc/src/gprs/Makefile.am
@@ -14,7 +14,7 @@
 endif
 
 osmo_gbproxy_SOURCES =  gb_proxy.c gb_proxy_main.c gb_proxy_vty.c \
-			gb_proxy_patch.c gb_proxy_tlli.c \
+			gb_proxy_patch.c gb_proxy_tlli.c gb_proxy_peer.c \
 			gprs_gb_parse.c gprs_llc_parse.c crc24.c gprs_utils.c
 osmo_gbproxy_LDADD = 	$(top_builddir)/src/libcommon/libcommon.a \
 			$(OSMO_LIBS)