qcacld-3.0: 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.

Change-Id: Id0fdeae6e6b71f53d3b73322aca659254d52cec8
CRs-Fixed: 2491452
diff --git a/Kbuild b/Kbuild
index 83d45ab..46119eb 100644
--- a/Kbuild
+++ b/Kbuild
@@ -54,7 +54,6 @@
 		$(HDD_SRC_DIR)/wlan_hdd_cfg80211.o \
 		$(HDD_SRC_DIR)/wlan_hdd_data_stall_detection.o \
 		$(HDD_SRC_DIR)/wlan_hdd_driver_ops.o \
-		$(HDD_SRC_DIR)/wlan_hdd_ext_scan.o \
 		$(HDD_SRC_DIR)/wlan_hdd_ftm.o \
 		$(HDD_SRC_DIR)/wlan_hdd_hostapd.o \
 		$(HDD_SRC_DIR)/wlan_hdd_ioctl.o \
@@ -77,6 +76,10 @@
 	    $(HDD_SRC_DIR)/wlan_hdd_hostapd_wext.o
 endif
 
+ifeq ($(CONFIG_FEATURE_WLAN_EXTSCAN), y)
+HDD_OBJS += $(HDD_SRC_DIR)/wlan_hdd_ext_scan.o
+endif
+
 ifeq ($(CONFIG_WLAN_DEBUGFS), y)
 HDD_OBJS += $(HDD_SRC_DIR)/wlan_hdd_debugfs.o
 ifeq ($(CONFIG_WLAN_FEATURE_LINK_LAYER_STATS), y)