ARM: uniphier: refactor MEMCONF init code

Currently, memconf-sld3.c and memconf-pxs2.c duplicate the code.

There are 3 patterns in terms of MEMCONF init:
  - DRAM 2 channels: LD4, sLD8, Pro4, Pro5, LD11
  - DRAM 3 channels: sLD3
  - DRAM 3 channels (Ch2 is disable by MEMCONF[21]): Pxs2, LD20

All of them can be moved into a single file by a little more
refactoring.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/Makefile b/arch/arm/mach-uniphier/Makefile
index ae78548..98b42a0 100644
--- a/arch/arm/mach-uniphier/Makefile
+++ b/arch/arm/mach-uniphier/Makefile
@@ -4,7 +4,8 @@
 
 ifdef CONFIG_SPL_BUILD
 
-obj-y += init/ bcu/ memconf/
+obj-y += memconf.o
+obj-y += init/ bcu/
 obj-$(CONFIG_MICRO_SUPPORT_CARD) += sbc/
 
 else