ARM: UniPhier: consolidate board_postclk_init() function

This commit merges
  arch/arm/cpu/armv7/uniphier/ph1-*/board_postclk_init.c
to
  arch/arm/cpu/armv7/uniphier/board_postclk_init.c

Because PH1-Pro4 does not have the BCU block, add __weak to
bcu_init().

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/arch/arm/cpu/armv7/uniphier/Makefile b/arch/arm/cpu/armv7/uniphier/Makefile
index dd57469..0f64d25 100644
--- a/arch/arm/cpu/armv7/uniphier/Makefile
+++ b/arch/arm/cpu/armv7/uniphier/Makefile
@@ -8,6 +8,7 @@
 obj-y += timer.o
 obj-y += reset.o
 obj-y += cache_uniphier.o
+obj-$(CONFIG_BOARD_POSTCLK_INIT) += board_postclk_init.o
 obj-y += dram_init.o
 obj-$(CONFIG_DISPLAY_CPUINFO) += cpu_info.o
 obj-$(CONFIG_BOARD_LATE_INIT) += board_late_init.o