iwlwifi: mvm: Add marker command 0xcb

Add Marker command.
The marker command send the ucode the time of sending the command in
milliseconds since 1970-01-01 00:00:00 UTC, in addition to other metatdata.
The ucode inserts this information into the usniffer logs, and returns the GP2
time stamp inside the command response.

Signed-off-by: Matti Gottlieb <matti.gottlieb@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>