[media] smiapp: Support V4L2_SEL_TGT_NATIVE_SIZE

Add support for selection target V4L2_SEL_TGT_NATIVE_SIZE. It is equivalent
of what V4L2_SEL_TGT_CROP_BOUNDS used to be. Support for
V4L2_SEL_TGT_CROP_BOUNDS is still supported by the driver as a compatibility
interface.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>