kbuild: consolidate PLATFORM_LIBS

We had switched to Kbuild so now we can specify
PLATFORM_LIBS/PLATFORM_LIBGCC with relative path.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Tom Rini <trini@ti.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index 17b7408..1db80be 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -67,13 +67,8 @@
 # times. Also, the prefix needs to be different based on whether
 # CONFIG_SPL_BUILD is defined or not. 'filter-out' the existing entry
 # before adding the correct one.
-ifdef CONFIG_SPL_BUILD
-PLATFORM_LIBS := $(SPLTREE)/arch/arm/lib/eabi_compat.o \
-	$(filter-out %/arch/arm/lib/eabi_compat.o, $(PLATFORM_LIBS))
-else
-PLATFORM_LIBS := $(OBJTREE)/arch/arm/lib/eabi_compat.o \
-	$(filter-out %/arch/arm/lib/eabi_compat.o, $(PLATFORM_LIBS))
-endif
+PLATFORM_LIBS := arch/arm/lib/eabi_compat.o \
+	$(filter-out arch/arm/lib/eabi_compat.o, $(PLATFORM_LIBS))
 endif
 
 # needed for relocation