[media] s5p-fimc: Keep local copy of sensors platform data

Use a copy of sensor platform data structure, rather than referencing
external platform data from the driver. This allows to fill the local
copy with values parsed from device tree when needed.

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>