Clean up the code a little by dropping the now unnecessary switch case
in drm_output_init_pixman(). As a side effect, this enables all formats
that have a pixman_format entry in the pixel format table:
- rgb565
- xrgb8888
- argb8888
- xbgr8888
- abgr8888
- rgbx8888
- rgba8888
- bgrx8888
- bgra8888
- xrgb2101010
- argb2101010
- xbgr2101010
- abgr2101010
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>