platform/x86: asus-wmi: Fix kbd_dock_devid tablet-switch reporting

Commit 1ea0d3b4 ("platform/x86: asus-wmi: Simplify tablet-mode-switch
handling") unified the asus-wmi tablet-switch handling, but it did not take
into account that the value returned for the kbd_dock_devid WMI method is
inverted where as the other ones are not inverted.

This causes asus-wmi to report an inverted tablet-switch state for devices
which use the kbd_dock_devid, which causes libinput to ignore touchpad
events while the affected T10x model 2-in-1s are docked.

Add inverting of the return value in the kbd_dock_devid case to fix this.

Fixes: 1ea0d3b4 ("platform/x86: asus-wmi: Simplify tablet-mode-switch handling")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230120143441.527334-1-hdegoede@redhat.com