media: atomisp: replace ia_css_region with v4l2_rect

media: atomisp: replace ia_css_region with v4l2_rect

The struct ia_css_region definition is redundant as struct v4l2_rect
provides the same functionality (left, top, width, height) and is the
standard V4L2 type.

Replace usage of ia_css_region with v4l2_rect in ia_css_dz_config
and remove the definition of ia_css_region from ia_css_types.h.

Also remove historical comments referencing the addition of zoom_region
and include <linux/videodev2.h> to support the v4l2_rect type.

Signed-off-by: Karthikey Kadati <karthikey3608@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>