platform/x86: toshiba: re-enable acpi hotkeys after suspend to disk

On the Toshiba Tecra Z40, after a suspend-to-disk, some FN hotkeys
driven by toshiba_acpi are not functional.

Calling the ACPI object ENAB on resume makes them back alive.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>