ARM: rockchip: add sram dt nodes and documentation

Add dt-nodes for the sram on rk3066 and rk3188 including the reserved section
needed for smp bringup.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Ulrich Prinz <ulrich.prinz@googlemail.com>

Documentation/devicetree/bindings/arm/rockchip/smp-sram.txt

+Rockchip SRAM for smp bringup:
+------------------------------
+
+Rockchip's smp-capable SoCs use the first part of the sram for the bringup
+of the cores. Once the core gets powered up it executes the code that is
+residing at the very beginning of the sram.
+
+Therefore a reserved section sub-node has to be added to the mmio-sram
+declaration.
+
+Required sub-node properties:
+- compatible : should be "rockchip,rk3066-smp-sram"
+
+The rest of the properties should follow the generic mmio-sram discription
+found in ../../misc/sram.txt
+
+Example:
+
+	sram: sram@10080000 {
+		compatible = "mmio-sram";
+		reg = <0x10080000 0x10000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		smp-sram@10080000 {
+			compatible = "rockchip,rk3066-smp-sram";
+			reg = <0x10080000 0x50>;
+		};
+	};

arch/arm/boot/dts/rk3066a.dtsi

@@ -64,6 +64,19 @@ timer@2000e000 {
 			clock-names = "timer", "pclk";
 		};
 
+		sram: sram@10080000 {
+			compatible = "mmio-sram";
+			reg = <0x10080000 0x10000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 0x10080000 0x10000>;
+
+			smp-sram@0 {
+				compatible = "rockchip,rk3066-smp-sram";
+				reg = <0x0 0x50>;
+			};
+		};
+
 		pinctrl@20008000 {
 			compatible = "rockchip,rk3066a-pinctrl";
 			reg = <0x20008000 0x150>;

arch/arm/boot/dts/rk3188.dtsi

@@ -60,6 +60,19 @@ local-timer@1013c600 {
 			interrupts = <GIC_PPI 13 0xf04>;
 		};
 
+		sram: sram@10080000 {
+			compatible = "mmio-sram";
+			reg = <0x10080000 0x8000>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 0x10080000 0x8000>;
+
+			smp-sram@0 {
+				compatible = "rockchip,rk3066-smp-sram";
+				reg = <0x0 0x50>;
+			};
+		};
+
 		pinctrl@20008000 {
 			compatible = "rockchip,rk3188-pinctrl";
 			reg = <0x20008000 0xa0>,