qcacld-3.0: Enable 6GHz feature for WHUNT

1. Add whunt_defconfig for whunt target. New Features can be
enabled in it to run related whunt test cases.

2. Enable CONFIG_BAND_6GHZ and CONFIG_WLAN_FEATURE_11AX
for whunt 6GHz test.

Change-Id: I63b84086cbf28e1fe3ab44bedb4977e73212af29
CRs-Fixed: 2550575

configs/whunt_defconfig

@@ -0,0 +1,7 @@
+#Enable 6 GHz Band
+CONFIG_BAND_6GHZ := y
+
+#Enable 11AX Feature
+CONFIG_WLAN_FEATURE_11AX := y
+
+include $(WLAN_ROOT)/configs/default_defconfig