pcu_sock: print OML alerts from PCU

The PCU is able to send OML alerts via the BTS to the BSC. When the PCU
operates in co-location to the BSC we just print the alerts in the log
directly

Change-Id: Id32553556356c2affe32e47ae1c3ae6a514efdce
Related: OS#5198

src/osmo-bsc/pcu_sock.c

@@ -686,6 +686,9 @@ static int pcu_rx_txt_ind(struct gsm_bts *bts,
 		if (rc < 0)
 			return -EINVAL;
 		break;
+	case PCU_OML_ALERT:
+		LOG_BTS(bts, DPCU, LOGL_ERROR, "PCU external alarm: %s\n", txt->text);
+		break;
 	default:
 		LOGP(DPCU, LOGL_ERROR, "Unknown TXT_IND type %u received\n",
 		     txt->type);