ARM: uniphier: refactor board_init()

The code here is cluttered due to the switch statement.  Introduce a
table of callbacks to clean up the initialization code across SoCs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/clk/Makefile b/arch/arm/mach-uniphier/clk/Makefile
index 765660f..bf77fca 100644
--- a/arch/arm/mach-uniphier/clk/Makefile
+++ b/arch/arm/mach-uniphier/clk/Makefile
@@ -24,7 +24,7 @@
 obj-$(CONFIG_ARCH_UNIPHIER_PXS2)	+= clk-pxs2.o
 obj-$(CONFIG_ARCH_UNIPHIER_LD6B)	+= clk-pxs2.o
 obj-$(CONFIG_ARCH_UNIPHIER_LD11)	+= clk-ld11.o pll-ld11.o
-obj-$(CONFIG_ARCH_UNIPHIER_LD20)	+= clk-ld20.o pll-ld20.o
+obj-$(CONFIG_ARCH_UNIPHIER_LD20)	+= pll-ld20.o
 
 endif