arm64: dts: uniphier: fix size of sdctrl node

All registers are located within 0x400 size from the base address.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/arm64/boot/dts/socionext/uniphier-ld20.dtsi

@@ -320,7 +320,7 @@ smpctrl@59801000 {
 		sdctrl@59810000 {
 			compatible = "socionext,uniphier-ld20-sdctrl",
 				     "simple-mfd", "syscon";
-			reg = <0x59810000 0x800>;
+			reg = <0x59810000 0x400>;
 
 			sd_clk: clock {
 				compatible = "socionext,uniphier-ld20-sd-clock";