platform/x86: wmi: Fix refcounting of WMI devices in legacy functions

platform/x86: wmi: Fix refcounting of WMI devices in legacy functions

Until now, legacy GUID-based functions where using find_guid() when
searching for WMI devices, which did no refcounting on the returned
WMI device. This meant that the WMI device could disappear at any
moment, potentially leading to various errors. Fix this by using
bus_find_device() which returns an actual reference to the found
WMI device.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>