ARM: uniphier: add eMMC boot support

Export device nodes needed for eMMC boot (eMMC node, pinctrl, and
clock) to the SPL DTB.  CONFIG_SUPPORT_EMMC_BOOT is also necessary
to use "mmc partconf" command.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/dts/uniphier-proxstream2-gentil.dts b/arch/arm/dts/uniphier-proxstream2-gentil.dts
index c3551fe..eb1d2bc 100644
--- a/arch/arm/dts/uniphier-proxstream2-gentil.dts
+++ b/arch/arm/dts/uniphier-proxstream2-gentil.dts
@@ -75,6 +75,14 @@
 	u-boot,dm-pre-reloc;
 };
 
+&mio {
+	u-boot,dm-pre-reloc;
+};
+
+&emmc {
+	u-boot,dm-pre-reloc;
+};
+
 &pinctrl {
 	u-boot,dm-pre-reloc;
 };
@@ -82,3 +90,7 @@
 &pinctrl_uart2 {
 	u-boot,dm-pre-reloc;
 };
+
+&pinctrl_emmc {
+	u-boot,dm-pre-reloc;
+};