platform/x86: intel_int0002_vgpio: Only call enable_irq_wake() when using s2idle

Commit 871f1f2b ("platform/x86: intel_int0002_vgpio: Only implement
irq_set_wake on Bay Trail") stopped passing irq_set_wake requests on to
the parents IRQ because this was breaking suspend (causing immediate
wakeups) on an Asus E202SA.

This workaround for the Asus E202SA is causing wakeup by USB keyboard to
not work on other devices with Airmont CPU cores such as the Medion Akoya
E1239T. In hindsight the problem with the Asus E202SA has nothing to do
with Silvermont vs Airmont CPU cores, so the differentiation between the
2 types of CPU cores introduced by the previous fix is wrong.

The real issue at hand is s2idle vs S3 suspend where the suspend is
mostly handled by firmware. The parent IRQ for the INT0002 device is shared
with the ACPI SCI and the real problem is that the INT0002 code should not
be messing with the wakeup settings of that IRQ when suspend/resume is
being handled by the firmware.

Note that on systems which support both s2idle and S3 suspend, which
suspend method to use can be changed at runtime.

This patch fixes both the Asus E202SA spurious wakeups issue as well as
the wakeup by USB keyboard not working on the Medion Akoya E1239T issue.

These are both fixed by replacing the old workaround with delaying the
enable_irq_wake(parent_irq) call till system-suspend time and protecting
it with a !pm_suspend_via_firmware() check so that we still do not call
it on devices using firmware-based (S3) suspend such as the Asus E202SA.

Note rather then adding #ifdef CONFIG_PM_SLEEP, this commit simply adds
a "depends on PM_SLEEP" to the Kconfig since this drivers whole purpose
is to deal with wakeup events, so using it without CONFIG_PM_SLEEP makes
no sense.

Cc: Maxim Mikityanskiy <maxtram95@gmail.com>
Fixes: 871f1f2b ("platform/x86: intel_int0002_vgpio: Only implement irq_set_wake on Bay Trail")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20210512125523.55215-2-hdegoede@redhat.com