media: Revert "media: exynos4-is: Remove dependency on obsolete SoC support"

Support for the Exynos4212 SoC was originally dropped as there were
no boards using it. We will be adding a device that uses it, so add
it back.

This reverts commit 2d41a0c9.

Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>