[media] s5p-fimc: Add variant data structure for Exynos4x12

Add variant data structures for Exynos4212 and Exynos4412 SoC.
Add 'const' qualifier for the variant description structures.
Also remove has_cam_if flags from FIMC3 on Exynos4210 SoC is
it has no interconnections the camera ports.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>