iwlwifi: mvm: add basic Time of Flight (802.11mc FTM) support

ToF is a time based method for measurement of the WiFi device
location within a WiFi environment. The driver functionality provided
by this patch is the interface for communication with FW and receiving
location related updates from the FW. The interface provided by this
patch is via debugfs.

Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>