ARM: uniphier: check DT to determine whether to initialize SBC

If CONFIG_MICRO_SUPPORT_CARD is enabled, U-Boot initialize SBC
(System Bus Controller), which may not be really necessary.

Check the "socionext,uniphier-system-bus" node in DT run-time.
If and only if it is found and its "status" property is okay,
initialize the SBC block.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/Makefile b/arch/arm/mach-uniphier/Makefile
index d0c39d42..caa79d1 100644
--- a/arch/arm/mach-uniphier/Makefile
+++ b/arch/arm/mach-uniphier/Makefile
@@ -18,13 +18,14 @@
 obj-y += reset.o
 endif
 
-obj-$(CONFIG_MICRO_SUPPORT_CARD) += sbc/ micro-support-card.o
+obj-$(CONFIG_MICRO_SUPPORT_CARD) += micro-support-card.o
 obj-y += pinctrl-glue.o
 obj-$(CONFIG_MMC) += mmc-first-dev.o
 obj-y += fdt-fixup.o
 
 endif
 
+obj-y += sbc/
 obj-y += soc-info.o
 obj-y += boot-device/
 obj-y += clk/