ARM: dts: tegra20: Update Memory Controller node to the new binding

Device tree binding of Memory Controller has been changed: GART has been
squashed into the MC, there are a new mandatory clock and #iommu-cells
properties, the compatible has been changed to 'tegra20-mc-gart'.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

arch/arm/boot/dts/tegra20.dtsi

@@ -616,17 +616,14 @@ pmc@7000e400 {
 	};
 
 	mc: memory-controller@7000f000 {
-		compatible = "nvidia,tegra20-mc";
-		reg = <0x7000f000 0x024
-		       0x7000f03c 0x3c4>;
+		compatible = "nvidia,tegra20-mc-gart";
+		reg = <0x7000f000 0x400		/* controller registers */
+		       0x58000000 0x02000000>;	/* GART aperture */
+		clocks = <&tegra_car TEGRA20_CLK_MC>;
+		clock-names = "mc";
 		interrupts = <GIC_SPI 77 IRQ_TYPE_LEVEL_HIGH>;
 		#reset-cells = <1>;
-	};
-
-	iommu@7000f024 {
-		compatible = "nvidia,tegra20-gart";
-		reg = <0x7000f024 0x00000018	/* controller registers */
-		       0x58000000 0x02000000>;	/* GART aperture */
+		#iommu-cells = <0>;
 	};
 
 	memory-controller@7000f400 {