drm/exynos: add device tree support for rotator

The exynos4 platform is only dt-based since 3.10, we should convert driver data
and ids to dt-based parsing methods. The rotator driver has a limit table to get
size limit of input picture. Each SoCs has slightly different limit value
compared with any others.
For example, exynos4210's max_size of RGB888 is 16k x 16k. But, others have
8k x 8k. Another example the exynos5250 should have multiple of 2 pixel size
for its X/Y axis. Thus, we should keep different tables for each of them.
This patch also includes desciptions of each nodes for the rotator and specifies
a example how to bind it.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>