prima: extscan: Fix to avoid compatibility issues

Ext scan structures are changed as part of ext scan enhancements.
Add check for feature capability EXT_SCAN_ENHANCED from firmware
before sending enhanced structure to avoid compatibility issues
between host and firmware.

Change-Id: Iaa00a2f9873b8276901a0d7ea308d68aa7e3a748
CRs-Fixed: 921922
diff --git a/riva/inc/wlan_hal_msg.h b/riva/inc/wlan_hal_msg.h
index 27dc4d3..cafff2c 100644
--- a/riva/inc/wlan_hal_msg.h
+++ b/riva/inc/wlan_hal_msg.h
@@ -6803,6 +6803,7 @@
     MGMT_FRAME_LOGGING     = 53,
     ENHANCED_TXBD_COMPLETION = 54,
     LOGGING_ENHANCEMENT    = 55,
+    EXT_SCAN_ENHANCED      = 56,
     MEMORY_DUMP_SUPPORTED  = 57,
     PER_PKT_STATS_SUPPORTED  = 58,
     MAX_FEATURE_SUPPORTED  = 128,