media: s5p-jpeg: disable encoder/decoder in exynos4-like hardware after use

Clearing the bits turns off the encoder/decoder. If the hardware
is not turned off after use, at subsequent uses it does not work
in a stable manner, resulting in incorrect interrupt status value
being read and e.g. erroneous read of compressed bitstream size.

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@s-opensource.com>