qcacld-3.0: Add get valid channels entry to NLA policy

qcacld-2.0 to qcacld-3.0 Propagation.

improper validation of
QCA_WLAN_VENDOR_ATTR_EXTSCAN_GET_VALID_CHANNELS_CONFIG_PARAM_MAX_CHANNELS.

validate QCA_WLAN_VENDOR_ATTR_EXTSCAN_GET_VALID_CHANNELS_CONFIG_PARAM_MAX_CHANNELS.

CRs-Fixed: 2053000
Change-Id: I16e5808492b5b35dc8b646af45d6ac6d65561804

core/hdd/src/wlan_hdd_ext_scan.c

@@ -64,6 +64,8 @@ static const struct nla_policy wlan_hdd_extscan_config_policy
 				.type = NLA_U32},
 	[QCA_WLAN_VENDOR_ATTR_EXTSCAN_GET_VALID_CHANNELS_CONFIG_PARAM_WIFI_BAND] = {
 				.type = NLA_U32},
+	[QCA_WLAN_VENDOR_ATTR_EXTSCAN_GET_VALID_CHANNELS_CONFIG_PARAM_MAX_CHANNELS] = {
+				.type = NLA_U32},
 	[QCA_WLAN_VENDOR_ATTR_EXTSCAN_CHANNEL_SPEC_CHANNEL] = {.type = NLA_U32},
 	[QCA_WLAN_VENDOR_ATTR_EXTSCAN_CHANNEL_SPEC_DWELL_TIME] = {
 				.type = NLA_U32},