gbproxy: Track TLLI even when the IMSI is not known

Currently only TLLIs for which it is known that they may be patched
are put into the TLLI list.

This patch changes this to add TLLIs even when the IMSI is not yet
known. A enable_patching flag is added to the gbproxy_tlli_info
structure to control patching.

Note that this puts every active TLLI into the list where accesses
are O(N) currently.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/include/openbsc/gb_proxy.h b/openbsc/include/openbsc/gb_proxy.h
index 3f81551..5a580cd 100644
--- a/openbsc/include/openbsc/gb_proxy.h
+++ b/openbsc/include/openbsc/gb_proxy.h
@@ -88,6 +88,8 @@
 	time_t timestamp;
 	uint8_t *mi_data;
 	size_t mi_data_len;
+
+	int enable_patching;
 };