ARM: socfpga: dts: add "altr,modrst-offset" property

The "altr,modrst-offset" property represents the offset into the reset manager
that is the first register to be used by the driver to bring peripherals out
of reset.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>

Documentation/devicetree/bindings/reset/socfpga-reset.txt

@@ -3,6 +3,7 @@ Altera SOCFPGA Reset Manager
 Required properties:
 - compatible : "altr,rst-mgr"
 - reg : Should contain 1 register ranges(address and length)
+- altr,modrst-offset : Should contain the offset of the first modrst register.
 - #reset-cells: 1
 
 Example:
@@ -10,4 +11,5 @@ Example:
 		#reset-cells = <1>;
 		compatible = "altr,rst-mgr";
 		reg = <0xffd05000 0x1000>;
+		altr,modrst-offset = <0x10>;
 	};

arch/arm/boot/dts/socfpga.dtsi

@@ -752,6 +752,7 @@
 			#reset-cells = <1>;
 			compatible = "altr,rst-mgr";
 			reg = <0xffd05000 0x1000>;
+			altr,modrst-offset = <0x10>;
 		};
 
 		usbphy0: usbphy@0 {

arch/arm/boot/dts/socfpga_arria10.dtsi

@@ -588,6 +588,7 @@
 			#reset-cells = <1>;
 			compatible = "altr,rst-mgr";
 			reg = <0xffd05000 0x100>;
+			altr,modrst-offset = <0x20>;
 		};
 
 		scu: snoop-control-unit@ffffc000 {