[media] s5p-fimc: Use dynamic debug

[media] s5p-fimc: Use dynamic debug

Use pr_debug instead of printk so it is possible to control
debug traces at runtime.
E.g. to enable debug trace in file fimc-core.c use command:
echo -n 'file fimc-core.c +p' > /sys/kernel/debug/dynamic_debug/control
or
echo -n 'file fimc-core.c -p' > /sys/kernel/debug/dynamic_debug/control
to disable.

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>