ARM: dt: tegra: configure power off for some boards

For Seaboard, Ventana, and Cardhu, add DT property to tell the regulator
that it should provide the pm_power_off() implementation. This allows
"shutdown" to work.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/boot/dts/tegra30-cardhu.dtsi b/arch/arm/boot/dts/tegra30-cardhu.dtsi
index 4794693..d10c9c5 100644
--- a/arch/arm/boot/dts/tegra30-cardhu.dtsi
+++ b/arch/arm/boot/dts/tegra30-cardhu.dtsi
@@ -156,6 +156,8 @@
 			#interrupt-cells = <2>;
 			interrupt-controller;
 
+			ti,system-power-controller;
+
 			#gpio-cells = <2>;
 			gpio-controller;