gpu: ipu-v3: Restore RGB32, BGR32

RGB32 and BGR32 formats were inadvertently removed from the switch
statement in ipu_pixelformat_to_colorspace(). Restore them.

Fixes: a5995717

 ("gpu: ipu-v3: enable remaining 32-bit RGB V4L2 pixel formats")
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>