x86, olpc-xo15-sci: Enable EC wakeup capability

Some recent changes to the way that ACPI handles wakeup flags
means that the XO15EC ACPI device is not wakeup-capable by
default so device_set_wakeup_enable() does nothing.

Use device_init_wakeup() to mark the device as wakeup capable,
and to enable wakeups.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/20110724173430.BE03C9D401C@zog.reactivated.net


Signed-off-by: Ingo Molnar <mingo@elte.hu>