qcacmn: Add host support for db2dbm RSSI changes

Add host support for db2dbm RSSI changes. Firmware
indicates this capability when underlying hardware
has RSSI reporting feature. Based on this capability
host will know if firmware sends SNR or RSSI. If no
capablity is present then host will convert SNR to
rssi using a fixed offset of -96. If capability is
present host will directly use the rssi as it is.

Change-Id: I9058f16c6280d466feb96cf88a8a0d8cd7b02032
CRs-Fixed: 2364025

wmi_unified_param.h

@@ -4569,7 +4569,7 @@ struct wmi_host_per_chain_rssi_stats {
  */
 typedef struct {
 	wmi_host_mac_addr peer_macaddr;
-	uint32_t  peer_rssi;
+	int8_t  peer_rssi;
 	uint32_t  peer_rssi_seq_num;
 	uint32_t  peer_tx_rate;
 	uint32_t  peer_rx_rate;
@@ -5274,6 +5274,7 @@ typedef enum {
 	wmi_service_nan_sap_support,
 	wmi_service_ndi_sap_support,
 	wmi_service_nan_disable_support,
+	wmi_service_hw_db2dbm_support,
 	wmi_services_max,
 } wmi_conv_service_ids;
 #define WMI_SERVICE_UNAVAILABLE 0xFFFF