drm/exynos: add device tree support for fimc ipp driver

This patch adds OF initialization support for the FIMC driver.
The binding documentation can be found at Documentation/devicetree/
bindings/media/samsung-fimc.txt.

The syscon regmap interface is used to serialize access to the
shared CAMBLK registers from within the V4L2 FIMC-IS and the DRM
FIMC drivers. The DRM driver uses this interface for setting up
the FIFO data link between FIMD and FIMC IP blocks, while the V4L2
one for setting up a data link between the camera ISP and FIMC for
camera capture. The CAMBLK registers are not accessed any more
through a statically mapped IO. Synchronized access to these
registers is required for simultaneous operation of the camera
ISP and the DRM IPP on Exynos4x12.

The driver data and driver_ids static data structures are removed
since Exynos4 is going to be a dt-only platform and there is
currently no board file in mainline that defines platform data
for the FIMC IPP, i.e. uses it.

Camera input signal polarities are not currently parsed from the
device tree.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>