media: exynos4-is: fimc-is: Fully open-code compatible for grepping

It is very useful to find driver implementing compatibles with `git grep
compatible`, so driver should not use defines for that string, even if
this means string will be effectively duplicated.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>