x86: specify CONFIG_USE_PRIVATE_LIBGCC more simply

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>

arch/x86/config.mk

@@ -29,6 +29,4 @@ LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3
 LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3
 
 export NORMAL_LIBGCC = $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
-PREFIXED_LIBGCC = $(OBJTREE)/arch/$(ARCH)/lib/$(shell basename $(NORMAL_LIBGCC))
-
-CONFIG_USE_PRIVATE_LIBGCC=$(shell dirname $(PREFIXED_LIBGCC))
+CONFIG_USE_PRIVATE_LIBGCC := arch/x86/lib