dm: tegra: dts: Add aliases for spi on tegra30 boards

All boards with a SPI interface have a suitable spi alias except the tegra30
boards. Add these missing aliases.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/arch/arm/dts/tegra20-trimslice.dts b/arch/arm/dts/tegra20-trimslice.dts
index cee5cfe..74e8a16 100644
--- a/arch/arm/dts/tegra20-trimslice.dts
+++ b/arch/arm/dts/tegra20-trimslice.dts
@@ -15,6 +15,7 @@
 		usb1 = "/usb@c5000000";
 		sdhci0 = "/sdhci@c8000600";
 		sdhci1 = "/sdhci@c8000000";
+		spi0 = "/spi@7000c380";
 	};
 
 	memory {