platform/x86: Add lenovo-wmi-* driver Documentation

platform/x86: Add lenovo-wmi-* driver Documentation

Adds documentation for new lenovo-wmi drivers.

Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
Link: https://lore.kernel.org/r/20250702033826.1057762-2-derekjohn.clark@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>