drm/i915: Move VIDEO_DIP_CTL definitions to their right place.

The bits weren't defined in descending order.
v2: Move definitions in a separate patch (Manasi)

Cc: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181005185643.31660-2-dhinakaran.pandiyan@intel.com