qcacmn: Added new WMI vdev param support

New WMI vdev param will be used to send
MAX MTU size to firmware.

CRs-Fixed: 2467047
Change-Id: Ib6d0fb4e6782247900d5338f182c4424ea183410

wmi/inc/wmi_unified_param.h

@@ -5124,6 +5124,7 @@ typedef enum {
 	wmi_vdev_param_ul_stbc,
 	wmi_vdev_param_ul_fixed_rate,
 	wmi_vdev_param_rawmode_open_war,
+	wmi_vdev_param_max_mtu_size,
 } wmi_conv_vdev_param_id;
 
 /**