[media] exynos-gsc: Add copy time stamp handling

Since the introduction of the timestamp_type field, it is necessary that
the driver chooses which type it will use. This patch adds support for
the timestamp_type.

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>