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/tests/gbproxy/Makefile.am b/openbsc/tests/gbproxy/Makefile.am
index 5f5e582..f6dd785 100644
--- a/openbsc/tests/gbproxy/Makefile.am
+++ b/openbsc/tests/gbproxy/Makefile.am
@@ -10,6 +10,7 @@
 gbproxy_test_LDADD = \
 			$(top_builddir)/src/gprs/gb_proxy.o \
 			$(top_builddir)/src/gprs/gb_proxy_patch.o \
+			$(top_builddir)/src/gprs/gb_proxy_peer.o \
 			$(top_builddir)/src/gprs/gb_proxy_tlli.o \
 			$(top_builddir)/src/gprs/gprs_gb_parse.o \
 			$(top_builddir)/src/gprs/gprs_llc_parse.o \