ARM: tegra: Fix unit_address_vs_reg DTC warnings for /memory

Add a generic /memory node in each Tegra DTSI (with empty reg property,
to be overidden by each DTS) and set proper unit address for /memory
nodes to fix the DTC warnings:

    arch/arm/boot/dts/tegra20-harmony.dtb: Warning (unit_address_vs_reg):
        /memory: node has a reg or ranges property, but no unit name

The DTB after the change is the same as before except adding
unit-address to /memory node.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/arch/arm/boot/dts/tegra124-jetson-tk1.dts b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
index 6dbcf84..9151b3e 100644
--- a/arch/arm/boot/dts/tegra124-jetson-tk1.dts
+++ b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
@@ -24,7 +24,7 @@
 		stdout-path = "serial0:115200n8";
 	};
 
-	memory {
+	memory@80000000 {
 		reg = <0x0 0x80000000 0x0 0x80000000>;
 	};