ARM: don't use -ffunction-sections/-fdata-sections with LTO build

When building with LTO, using -ffunction-sections/-fdata-sections is not
useful anymore.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/config.mk b/arch/arm/config.mk
index e79f010..f556ee3 100644
--- a/arch/arm/config.mk
+++ b/arch/arm/config.mk
@@ -16,8 +16,12 @@
 CFLAGS_EFI := -fpic -fshort-wchar
 
 LDFLAGS_FINAL += --gc-sections
-PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections \
-		     -fno-common -ffixed-r9
+
+ifndef CONFIG_LTO
+PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections
+endif
+
+PLATFORM_RELFLAGS += -fno-common -ffixed-r9
 PLATFORM_RELFLAGS += $(call cc-option, -msoft-float) \
       $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,))