media: staging: rkisp1: replace 3 fields 'ct_offset_*' with one array

The struct rkisp1_cif_isp_ctk_config contains 3 fields
ct_offset_{rgb}. Replace them with one array field 'ct_offset[3].

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>