[media] v4l: add support for selection api

This patch introduces new api for a precise control of cropping and composing
features for video devices. The new ioctls are VIDIOC_S_SELECTION and
VIDIOC_G_SELECTION.

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>