arm: dts: socfpga: stratix10: Fix memory node

Commit 5dfd5607af2114047bd ("ARM: socfpga: Pull DRAM size from DT") get
memory size from DT. So, we need to update memory size in memory node.
Otherwise, it cause U-boot hang.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>

arch/arm/dts/socfpga_stratix10_socdk.dts

@@ -36,8 +36,8 @@
 
 	memory {
 		device_type = "memory";
-		/* We expect the bootloader to fill in the reg */
-		reg = <0 0 0 0>;
+		reg = <0 0 0 0x80000000>; /* 2GB */
+		u-boot,dm-pre-reloc;
 	};
 };