ACPI / ACPICA: Do not check reference counters in acpi_ev_enable_gpe()

acpi_ev_enable_gpe() should enable the GPE at the hardware level
regardless of the value of the GPE's runtime reference counter.

There are only two callers of acpi_ev_enable_gpe(), acpi_enable_gpe()
and acpi_set_gpe().  The first one checks the GPE's runtime
reference counter itself and only calls acpi_ev_enable_gpe() if it's
equal to one, and the other one is supposed to enable the GPE
unconditionally (if called with ACPI_GPE_ENABLE).

This change fixes the problem in acpi_enable_wakeup_device() where
the GPE will not be enabled for wakeup if it's runtime reference
counter is zero, which is a regression from 2.6.33.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Robert Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>