media: sun6i-csi: Implement capture link validation with logic

Rework the capture link validate implementation with actual logic that
reflects the possibilities of the device instead of the combinatory helper
functions, using the added match list helper
sun6i_csi_is_format_supported() when needed. Remove the previous dedicated
helper.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>