ACPI: button: Enable wakeup GPEs for ACPI buttons at probe time

ACPI: button: Enable wakeup GPEs for ACPI buttons at probe time

Prior to commit 57c31e6d620f ("ACPI: scan: Use acpi_setup_gpe_for_wake()
for buttons"), ACPI button wakeup GPEs having handler methods remained
enabled after acpi_wakeup_gpe_init(), but currently they are not enabled
because acpi_setup_gpe_for_wake() disables them.

That causes function keys to stop working on some systems [1] and there
may be other related issues elsewhere.

To address that, make the ACPI button driver enable wakeup GPEs for ACPI
buttons so long as they have handler methods.  While this does not
restore the old behavior exactly (the ACPI button driver needs to be
bound to the button devices for the GPEs to be enabled), it should be
sufficient to restore the missing functionality.

For this purpose, introduce acpi_enable_gpe_cond() that enables
a GPE if its dispatch type matches the supplied one and modify
acpi_button_probe() to use that function for enabling the GPEs in
question.

Fixes: 57c31e6d620f ("ACPI: scan: Use acpi_setup_gpe_for_wake() for buttons")
Reported-by: Nick <nick@kousu.ca>
Closes: https://lore.kernel.org/linux-acpi/E2OXET.4X5GTP37VTNC3@kousu.ca/ [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Nick <nick@kousu.ca>
Cc: 7.0+ <stable@vger.kernel.org> # 7.0+
Link: https://patch.msgid.link/9629117.CDJkKcVGEf@rafael.j.wysocki