ARM: dts: uniphier: add u-boot, dm-pre-reloc to use eMMC boot on sLD3

The eMMC on sLD3 is assigned with dedicated pins (only multiplexed
with GPIO), so it shouldn't hurt to enable eMMC on SPL all the time.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/dts/uniphier-ph1-sld3-ref.dts b/arch/arm/dts/uniphier-ph1-sld3-ref.dts
index 099df83..0863588 100644
--- a/arch/arm/dts/uniphier-ph1-sld3-ref.dts
+++ b/arch/arm/dts/uniphier-ph1-sld3-ref.dts
@@ -85,3 +85,11 @@
 &serial0 {
        u-boot,dm-pre-reloc;
 };
+
+&mio {
+       u-boot,dm-pre-reloc;
+};
+
+&emmc {
+       u-boot,dm-pre-reloc;
+};