gsm_bts: add version and variant details

* add version string to gsm_bts
* add PCU version string to gsm_bts
* rename GSM_BTS_TYPE_OSMO_SYSMO -> GSM_BTS_OSMOBTS to avoid confusion
  between BTS model and variant
* add variant enum to gsm_bts_model using enum with variants for each
  hw vendor of OsmoBTS
* show connected PCU version (if available) in vty via 'show bts'

This will come in handy when logging details regarding particular BTS
reported via OML, see:

Related: OS#1614

Change-Id: I6710d53115f34634a7b70969cc05fd5c72ff8ab2
diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 66b30cd..c1882fc 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -245,6 +245,9 @@
 		bts->num_trx, VTY_NEWLINE);
 	vty_out(vty, "Description: %s%s",
 		bts->description ? bts->description : "(null)", VTY_NEWLINE);
+	if (strnlen(bts->pcu_version, MAX_VERSION_LENGTH))
+		vty_out(vty, "PCU version %s connected%s", bts->pcu_version,
+			VTY_NEWLINE);
 	vty_out(vty, "MS Max power: %u dBm%s", bts->ms_max_power, VTY_NEWLINE);
 	vty_out(vty, "Minimum Rx Level for Access: %i dBm%s",
 		rxlev2dbm(bts->si_common.cell_sel_par.rxlev_acc_min),
@@ -649,7 +652,7 @@
 		bts->early_classmark_allowed ? "allowed" : "forbidden", VTY_NEWLINE);
 	switch (bts->type) {
 	case GSM_BTS_TYPE_NANOBTS:
-	case GSM_BTS_TYPE_OSMO_SYSMO:
+	case GSM_BTS_TYPE_OSMOBTS:
 		vty_out(vty, "  ip.access unit_id %u %u%s",
 			bts->ip_access.site_id, bts->ip_access.bts_id, VTY_NEWLINE);
 		if (bts->ip_access.rsl_ip) {