media: sunxi: Add A10 CSI driver

The older CSI drivers have camera capture interface different from the one
in the newer ones.

This IP is pretty simple. Some variants (one controller out of two
instances on some SoCs) have an ISP embedded, but there's no code that make
use of it, so we ignored that part for now.

[Sakari Ailus: Wrapped a few long lines, set mbus code using a macro.]

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>