qcacmn: Disable ext scan in driver

Currently ext scan is enabled by default in driver which
is increasing driver size significantly and ext scan
is not getting used anymore.
Disable ext scan with feature flag CONFIG_FEATURE_WLAN_EXTSCAN
to reduce driver size and fix related compilation issue.

Change-Id: Id2344e6ed21caefa459773bb6e891ffb1e70cb92
CRs-Fixed: 2491455

umac/scan/core/src/wlan_scan_main.h

@@ -246,6 +246,7 @@ struct pno_def_config {
 };
 #endif
 
+#ifdef FEATURE_WLAN_EXTSCAN
 /**
  * struct extscan_def_config - def configuration for EXTSCAN
  * @extscan_enabled: enable extscan
@@ -261,6 +262,7 @@ struct extscan_def_config {
 	uint32_t extscan_active_max_chn_time;
 	uint32_t extscan_active_min_chn_time;
 };
+#endif
 
 /**
  * struct scan_default_params - default scan parameters to be used