qcacmn: WMI support added for sifs_trigger interval config

FR: TDMA Support for Wave2 Radios (host support)
Added a wmi cmd for configuring the interval between successive sifs
trigger frames given by the user app. Added a separate wmi cmd instead
of wmi param with reference to further scope.

Change-Id: Ifa778a761e3495ef7abab5f63a49661b307034ae
CRs-Fixed: 2330484

wmi_unified_priv.h

@@ -367,6 +367,9 @@ QDF_STATUS
 QDF_STATUS (*send_vdev_set_param_cmd)(wmi_unified_t wmi_handle,
 				struct vdev_set_params *param);
 
+QDF_STATUS (*send_vdev_sifs_trigger_cmd)(wmi_unified_t wmi_handle,
+					 struct sifs_trigger_param *param);
+
 QDF_STATUS (*send_stats_request_cmd)(wmi_unified_t wmi_handle,
 				uint8_t macaddr[IEEE80211_ADDR_LEN],
 				struct stats_request_params *param);