tegra: fdt: Add pwm binding and node

This binding will apparently soon be in linux-next. Bring it in now
since we need to do something, and may as well try to target what
Linux will have.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi
index d936b1e..3221bc9 100644
--- a/arch/arm/dts/tegra20.dtsi
+++ b/arch/arm/dts/tegra20.dtsi
@@ -211,4 +211,11 @@
 		compatible = "nvidia,tegra20-nand";
 		reg = <0x70008000 0x100>;
 	};
+
+	pwm: pwm@7000a000 {
+		compatible = "nvidia,tegra20-pwm";
+		reg = <0x7000a000 0x100>;
+		#pwm-cells = <2>;
+	};
+
 };