ARM: uniphier: move MMC code to a separate file

Currently, arch/arm/mach-uniphier/boot-mode/boot-mode.c is messed up
with unrelated code; there is no reason why the "mmcsetn" command
must be placed in this file.

Split out the MMC code into arch/arm/mach-uniphier/mmc-first-dev.c.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/Makefile b/arch/arm/mach-uniphier/Makefile
index 166b41f..0eb59fb 100644
--- a/arch/arm/mach-uniphier/Makefile
+++ b/arch/arm/mach-uniphier/Makefile
@@ -19,6 +19,7 @@
 
 obj-$(CONFIG_MICRO_SUPPORT_CARD) += sbc/ micro-support-card.o
 obj-y += pinctrl-glue.o
+obj-$(CONFIG_MMC) += mmc-first-dev.o
 
 endif