[media] s5p-fimc: Ensure proper s_stream() call order in the ISP datapaths

Since the FIMC-IS firmware communicates with an image sensor directly
through the ISP I2C bus controllers data streaming cannot be simply
enabled from left to right or disabled from right to left along the
processing pipeline. Thus a subdev index to call s_stream() on is
looked up from a table, rather than doing the op call based on
increasing/decreasing indexes.

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>