[media] v4l: s5p-tv: mixer: add support for selection API

This patch add support for V4L2 selection API to s5p-tv driver.  Moreover it
removes old API for cropping.  Old applications would still work because the
crop ioctls are emulated using the selection API.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>