ACPI: Use GPE reference counting to support shared GPEs

ACPI GPEs may map to multiple devices.  The current GPE interface
only provides a mechanism for enabling and disabling GPEs, making
it difficult to change the state of GPEs at runtime without extensive
cooperation between devices.

Add an API to allow devices to indicate whether or not they want
their device's GPE to be enabled for both runtime and wakeup events.

Remove the old GPE type handling entirely, which gets rid of various
quirks, like the implicit disabling with GPE type setting. This
requires a small amount of rework in order to ensure that non-wake
GPEs are enabled by default to preserve existing behaviour.

Based on patches from Matthew Garrett <mjg@redhat.com>.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>