staging: vboxvideo: Fixup some #ifdef-s

Add #ifdef CONFIG_PM_SLEEP around the suspend/hibernate functions.

Remove unnecessary #ifdef CONFIG_COMPAT, the .compat_ioctl member is
always available and if CONFIG_COMPAT is not set then drm_compat_ioctl
is defined to NULL.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>