alienware-wmi: WMAX interface documentation

Added documentation for new WMAX interface, present on some Alienware
X-Series, Alienware M-Series and Dell's G-Series laptops.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20241030001228.7770-1-kuurtb@gmail.com


Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>