[media] s5p-jpeg: add 5420 family support

JPEG IP found in Exynos5420 is similar to what is in Exynos3250, but
there are some subtle differences which this patch takes into account.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>