staging: bcm2835-codec: Correct g/s_selection API MPLANE support

The g_selection and s_selection API is messed up and requires
the driver to expect the non-MPLANE buffer types, not the MPLANE
ones even if they are supported. The V4L2 core will convert the
MPLANE ones to non-MPLANE should they be passed in

Fixes: 5e484a3e

 staging: bcm2835-codec: switch to multi-planar API
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>