[media] coda: move coda driver into its own directory

The coda driver has grown significantly and will continue to grow.
Move the coda driver into its own directory so it can be split.
Rename coda.h to coda_regs.h as it contains the register defines.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>