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

Support for Exynos4212 SoCs has been removed by commit bca9085e
("ARM: dts: exynos: remove Exynos4212 support (dead code)"), so there
is no need to keep remaining dead code related to this SoC version.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>