platform/x86: xo15-ebook: Fix wakeup source and GPE handling

platform/x86: xo15-ebook: Fix wakeup source and GPE handling

The device_set_wakeup_enable() call in ebook_switch_add() doesn't
actually do anything because power.can_wakeup is not set for ACPI
device objects.  Moreover, had it done anything, it would have
registered a wakeup source object that wouldn't have been used
going forward and that wakeup source would have been leaked after
driver removal because ebook_switch_remove() doesn't clean it up.
Accordingly, remove that call from ebook_switch_add().

Also prevent leaking an enabled ACPI GPE after removing the driver by
adding appropriate cleanup code to ebook_switch_remove().

Fixes: 89ca11771a4b ("OLPC XO-1.5 ebook switch driver")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/1966125.tdWV9SEqCh@rafael.j.wysocki
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>