[media] s5p-jpeg: Initialize cb and cr to zero

To avoid garbage value written into image base address planes,
initialize cb and cr of structure s5p_jpeg_addr to zero.

Signed-off-by: Tony K Nadackal <tony.kn@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>