Add a circular buffer to hold roaming related debug log information
for peer and vdev operations in the driver. Purpose is to dump
this information after host or target crash. 256 entries will go
back much deeper into history than dmesg or wlan driver logs found
in crashScope. Information is dumped out as error messages from
crash detection points as necessary.
The support routines help to store the debug logs and dump them,
typically after peer related timeout or assert.
wlan_roam_next_debug_log_index () - Utility routine to compute next index
wlan_roam_debug_log() - Adds a log entry
wlan_roam_debug_string() - Returns debug log type string
wlan_roam_debug_dump() - Dump all wlan roam debug log records
Add new QDF module ID QDF_MODULE_ID_ROAM_DEBUG.
CRs-Fixed: 1116078
Change-Id: If2077f560405ec0414d08ef4ece0fb0d2db2ccc7
