camera: Update FocusRegionPriorityMode index.
camera: Update FocusRegionPriorityMode index.

The enumeration element was renamed on DOMX from:
  OMX_TI_IMAGE_FocusRegionPriorityMode
to:
  OMX_IMAGE_FocusRegionPriorityMode

Signed-off-by: Daniel Diaz <ed054987dd20aebbd314fbb0d175066628f13717@ti.com>

mrchapp/gst-openmax,mrchapp/gst-openmax-devel,mrchapp/gst-openmax-devel,mrchapp/gst-openmax,mrchapp/gst-openmax,mrchapp/gst-openmax-devel