ARM: uniphier: compile board data only for SPL

Now U-Boot proper need not get the uniphier_boards array.  Compile
it only for SPL.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

arch/arm/mach-uniphier/Makefile

@@ -4,6 +4,7 @@
 
 ifdef CONFIG_SPL_BUILD
 
+obj-y += boards.o
 obj-y += spl_board_init.o
 obj-y += memconf.o
 obj-y += bcu/
@@ -21,7 +22,6 @@ obj-y += pinctrl-glue.o
 
 endif
 
-obj-y += boards.o
 obj-y += soc-info.o
 obj-y += boot-mode/
 obj-y += clk/