ACPI / ACPICA: Fix sysfs GPE interface

The sysfs interface allowing user space to disable/enable GPEs
doesn't work correctly, because a GPE disabled this way will be
re-enabled shortly by acpi_ev_asynch_enable_gpe() if it was
previosuly enabled by acpi_enable_gpe() (in which case the
corresponding bit in its enable register's enable_for_run mask is
set).

To address this issue make the sysfs GPE interface use
acpi_enable_gpe() and acpi_disable_gpe() instead of acpi_set_gpe()
so that GPE reference counters are modified by it along with the
values of GPE enable registers.

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