[media] exynos4-is: Use external s5k6a3 sensor driver

This patch removes the common fimc-is-sensor driver for image sensors
that are normally controlled by the FIMC-IS firmware. The FIMC-IS
driver now contains only a table of properties specific to each sensor.
The sensor properties required for the ISP's firmware are parsed from
device tree and retrieved from the internal table, which is selected
based on the compatible property of an image sensor.

To use the Exynos4x12 internal ISP the S5K6A3 sensor driver (drivers/
media/i2c/s5k6a3.c) is now required.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>