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>

Documentation/devicetree/bindings/gpu/samsung-rotator.txt

@@ -0,0 +1,27 @@
+* Samsung Image Rotator
+
+Required properties:
+  - compatible : value should be one of the following:
+	(a) "samsung,exynos4210-rotator" for Rotator IP in Exynos4210
+	(b) "samsung,exynos4212-rotator" for Rotator IP in Exynos4212/4412
+	(c) "samsung,exynos5250-rotator" for Rotator IP in Exynos5250
+
+  - reg : Physical base address of the IP registers and length of memory
+	  mapped region.
+
+  - interrupts : Interrupt specifier for rotator interrupt, according to format
+		 specific to interrupt parent.
+
+  - clocks : Clock specifier for rotator clock, according to generic clock
+	     bindings. (See Documentation/devicetree/bindings/clock/exynos*.txt)
+
+  - clock-names : Names of clocks. For exynos rotator, it should be "rotator".
+
+Example:
+	rotator@12810000 {
+		compatible = "samsung,exynos4210-rotator";
+		reg = <0x12810000 0x1000>;
+		interrupts = <0 83 0>;
+		clocks = <&clock 278>;
+		clock-names = "rotator";
+	};