Add support for the sink pad of scaler subdevice to respond
VIDIOC_G_SELECTION and VIDIOC_S_SELECTION ioctls with the following
targets: V4L2_SEL_TGT_COMPOSE_BOUNDS and V4L2_SEL_TGT_CROP.
* Add new const struct crop_rect_default to initialize subdev scaler
properly.
* Make changes in sink pad format reflect to the crop rectangle. E.g.
changing the frame format to a smaller size one can make the former
crop rectangle selects a non existing frame area. To solve this
situation the crop rectangle is clamped to the frame boundaries.
* Clamp crop rectangle respecting the sink bounds during set_selection
ioctl.