platform/x86: lg-laptop: Use ACPI device handle when evaluating WMAB/WMBB

[ Upstream commit b27ea279

 ]

On the LG Gram 16Z90S, the WMAB and WMBB ACPI methods are not mapped
under \XINI, but instead are mapped under \_SB.XINI.

The reason for this is that the LGEX0820 ACPI device used by this
driver is mapped at \_SB.XINI, so the ACPI methods where moved as well
to appear below the LGEX0820 ACPI device.

Fix this by using the ACPI handle from the ACPI device when evaluating
both methods.

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218901
Tested-by: Agathe Boutmy <agathe@boutmy.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20240606233540.9774-5-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>