ACPICA: Introduce acpi_dispatch_gpe()

Introduce acpi_dispatch_gpe() as a wrapper around acpi_ev_detect_gpe()
for checking if the given GPE (as represented by a GPE device handle
and a GPE number) is currently active and dispatching it (if that's
the case) outside of interrupt context.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>