platform/x86: wmi: Decouple legacy WMI notify handlers from wmi_block_list

Until now, legacy WMI notify handler functions where using the
wmi_block_list, 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.

Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240103192707.115512-4-W_Armin@gmx.de


Signed-off-by: Hans de Goede <hdegoede@redhat.com>