qcacld-3.0: Update linkspeed state to F/W for roaming protocol part

To avoid unmeaningful roaming, when low RSSI trigger,
only roam when rx linkspeed is also bad.
Steps:
1. F/W indicates feature supported by:
	wmi_service_linkspeed_roam_trigger_support
2. App sets vdev rx link speed threshold by vendor cmd.
3. Bus_bw_work gets rx link speed from data path periodically.
4. If found rx link speed change from good to poor, or poor to good, send
	to F/W.
5. F/W low rssi roaming is triggered only when both RSSI and link speed are
	poor.

Change-Id: I56829e42b26e407dd8e989a870aee2b3ea406232
CRs-Fixed: 3261996

components/mlme/dispatcher/inc/wlan_mlme_public_struct.h

@@ -1758,7 +1758,8 @@ struct fw_scan_channels {
 	uint32_t freq[NUM_CHANNELS];
 };
 
-/*
+/**
+ * struct wlan_mlme_lfr_cfg - MLME LMAC fast roaming config
  * @mawc_roam_enabled:              Enable/Disable MAWC during roaming
  * @enable_fast_roam_in_concurrency:Enable LFR roaming on STA during concurrency
  * @vendor_btm_param:               Vendor WTC roam trigger parameters