Add support for PCU version report

Expand 3GPP TS 52.021 ยง9.4.43 Probable Cause with Osmocom-specific value
for PCU version reporting to enable sending it via OML alarms.

Change-Id: If57459c0610f2c7b36d599b13087c8deef8bdd9e
Related: OS#1614
diff --git a/include/osmocom/gsm/protocol/gsm_12_21.h b/include/osmocom/gsm/protocol/gsm_12_21.h
index 23392d2..c88f0b1 100644
--- a/include/osmocom/gsm/protocol/gsm_12_21.h
+++ b/include/osmocom/gsm/protocol/gsm_12_21.h
@@ -277,6 +277,7 @@
 	OSMO_EVT_WARN_SW_WARN		= 0x0001,
 	/* External causes */
 	OSMO_EVT_EXT_ALARM		= 0xfeed,
+	OSMO_EVT_PCU_VERS		= 0xface,
 };
 
 extern const struct value_string abis_mm_event_cause_names[];
diff --git a/src/gsm/abis_nm.c b/src/gsm/abis_nm.c
index e1b248f..934d7ce 100644
--- a/src/gsm/abis_nm.c
+++ b/src/gsm/abis_nm.c
@@ -162,6 +162,7 @@
 	{ OSMO_EVT_MIN_PAG_TAB_FULL,	"Paging table full" },
 	{ OSMO_EVT_WARN_SW_WARN,	"Software warning" },
 	{ OSMO_EVT_EXT_ALARM,		"External alarm" },
+	{ OSMO_EVT_PCU_VERS,		"PCU version report" },
 	{ 0, NULL }
 };