ARM: dts: exynos: Fix LDO13 min values on Odroid XU3/XU4/HC1

From Odroid XU3/XU4/HC1 schematics the LDO13 regulator for SD2, can be
set on 1.8V or 2.8V so the minimal value should be fixed to 1.8V.  This
is necessary to support UHS-I tuning (otherwise card won't be detected
during boot).
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/boot/dts/exynos5422-odroid-core.dtsi

@@ -232,7 +232,7 @@ ldo12_reg: LDO12 {
 
 			ldo13_reg: LDO13 {
 				regulator-name = "vddq_mmc2";
-				regulator-min-microvolt = <2800000>;
+				regulator-min-microvolt = <1800000>;
 				regulator-max-microvolt = <2800000>;
 			};