ARM: tegra: define DT bindings for and instantiate timer

The Tegra timer provides a number of 29-bit timer channels, a single
32-bit free running counter, and in the Tegra30 variant, 5 watchdog modules.
The first two channels may also trigger a legacy watchdog reset.

Define a DT binding for this HW module, and add the module into the Tegra
device tree files.
Signed-off-by: Stephen Warren <swarren@nvidia.com>

Documentation/devicetree/bindings/timer/nvidia,tegra20-timer.txt

+NVIDIA Tegra20 timer
+
+The Tegra20 timer provides four 29-bit timer channels and a single 32-bit free
+running counter. The first two channels may also trigger a watchdog reset.
+
+Required properties:
+
+- compatible : should be "nvidia,tegra20-timer".
+- reg : Specifies base physical address and size of the registers.
+- interrupts : A list of 4 interrupts; one per timer channel.
+
+Example:
+
+timer {
+	compatible = "nvidia,tegra20-timer";
+	reg = <0x60005000 0x60>;
+	interrupts = <0 0 0x04
+			0 1 0x04
+			0 41 0x04
+			0 42 0x04>;
+};

Documentation/devicetree/bindings/timer/nvidia,tegra30-timer.txt

+NVIDIA Tegra30 timer
+
+The Tegra30 timer provides ten 29-bit timer channels, a single 32-bit free
+running counter, and 5 watchdog modules. The first two channels may also
+trigger a legacy watchdog reset.
+
+Required properties:
+
+- compatible : should be "nvidia,tegra30-timer", "nvidia,tegra20-timer".
+- reg : Specifies base physical address and size of the registers.
+- interrupts : A list of 6 interrupts; one per each of timer channels 1
+    through 5, and one for the shared interrupt for the remaining channels.
+
+timer {
+	compatible = "nvidia,tegra30-timer", "nvidia,tegra20-timer";
+	reg = <0x60005000 0x400>;
+	interrupts = <0 0 0x04
+		      0 1 0x04
+		      0 41 0x04
+		      0 42 0x04
+		      0 121 0x04
+		      0 122 0x04>;
+};

arch/arm/boot/dts/tegra20.dtsi

@@ -108,6 +108,15 @@ intc: interrupt-controller {
 		#interrupt-cells = <3>;
 	};
 
+	timer@60005000 {
+		compatible = "nvidia,tegra20-timer";
+		reg = <0x60005000 0x60>;
+		interrupts = <0 0 0x04
+			      0 1 0x04
+			      0 41 0x04
+			      0 42 0x04>;
+	};
+
 	apbdma: dma {
 		compatible = "nvidia,tegra20-apbdma";
 		reg = <0x6000a000 0x1200>;

arch/arm/boot/dts/tegra30.dtsi

@@ -108,6 +108,17 @@ intc: interrupt-controller {
 		#interrupt-cells = <3>;
 	};
 
+	timer@60005000 {
+		compatible = "nvidia,tegra30-timer", "nvidia,tegra20-timer";
+		reg = <0x60005000 0x400>;
+		interrupts = <0 0 0x04
+			      0 1 0x04
+			      0 41 0x04
+			      0 42 0x04
+			      0 121 0x04
+			      0 122 0x04>;
+	};
+
 	apbdma: dma {
 		compatible = "nvidia,tegra30-apbdma", "nvidia,tegra20-apbdma";
 		reg = <0x6000a000 0x1400>;