ns2: Add log filtering by NSE/NSEI, fix NSVC filter on receive

NSVC filtering was only implemented on sending messages, this also adds
log_set_context() calls to  ns2_recv_vc()
Filtering by NSE is implemented similar to NSVC.

Change-Id: I63c0e85f82f5d08c5a6f535da94b8648498439d2
Related: SYS#5232
diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 38b465c..418a42e 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -165,6 +165,7 @@
 	LOG_CTX_BSC_SUBSCR,
 	LOG_CTX_VLR_SUBSCR,
 	LOG_CTX_L1_SAPI,
+	LOG_CTX_GB_NSE,
 	_LOG_CTX_COUNT
 };
 
@@ -178,6 +179,7 @@
 	LOG_FLT_BSC_SUBSCR,
 	LOG_FLT_VLR_SUBSCR,
 	LOG_FLT_L1_SAPI,
+	LOG_FLT_GB_NSE,
 	_LOG_FLT_COUNT
 };