platform/x86: ideapad-laptop: Stop sending KEY_TOUCHPAD_TOGGLE

platform/x86: ideapad-laptop: Stop sending KEY_TOUCHPAD_TOGGLE

Commit 5829f8a897e4 ("platform/x86: ideapad-laptop: Send
KEY_TOUCHPAD_TOGGLE on some models") made ideapad-laptop send
KEY_TOUCHPAD_TOGGLE when we receive an ACPI notify with VPC event bit 5 set
and the touchpad-state has not been changed by the EC itself already.

This was done under the assumption that this would be good to do to make
the touchpad-toggle hotkey work on newer models where the EC does not
toggle the touchpad on/off itself (because it is not routed through
the PS/2 controller, but uses I2C).

But it turns out that at least some models, e.g. the Yoga 7-15ITL5 the EC
triggers an ACPI notify with VPC event bit 5 set on resume, which would
now cause a spurious KEY_TOUCHPAD_TOGGLE on resume to which the desktop
environment responds by disabling the touchpad in software, breaking
the touchpad (until manually re-enabled) on resume.

It was never confirmed that sending KEY_TOUCHPAD_TOGGLE actually improves
things on new models and at least some new models like the Yoga 7-15ITL5
don't have a touchpad on/off toggle hotkey at all, while still sending
ACPI notify events with VPC event bit 5 set.

So it seems best to revert the change to send KEY_TOUCHPAD_TOGGLE when
receiving an ACPI notify events with VPC event bit 5 and the touchpad
state as reported by the EC has not changed.

Note this is not a full revert the code to cache the last EC touchpad
state is kept to avoid sending spurious KEY_TOUCHPAD_ON / _OFF events
on resume.

Fixes: 5829f8a897e4 ("platform/x86: ideapad-laptop: Send KEY_TOUCHPAD_TOGGLE on some models")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217234
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230330194644.64628-1-hdegoede@redhat.com