Disable LTO only for Qemu ARM build

Keep flag enabled for HiSi cameras whereas
LTO will be disabled for Qemu as a workaround.
Signed-off-by: NZbigniew Bodek <zbigniew.bodek@huawei.com>
Change-Id: Iad7295d108dfea0928537281f87eb46836ee6681

tools/build/mk/los_config.mk

@@ -463,10 +463,14 @@ ifeq ($(LOSCFG_COMPILE_DEBUG), y)
     LITEOS_COPTS_OPTION  = -g -gdwarf-2
 else
     ifeq ($(LOSCFG_COMPILER_CLANG_LLVM), y)
-	# WORKAROUND: Disable LTO to avoid undefined __stack_chk_guard
-	#             problem. "externally_visible" attribute could be
-	#             a fix for that but it is not known to our LLVM.
-        LITEOS_COPTS_OPTMIZE = -Oz #-flto
+        ifeq ($(LOSCFG_PLATFORM_QEMU_ARM_VIRT_CA7), y)
+                # WORKAROUND: Disable LTO to avoid undefined __stack_chk_guard
+                #             problem. "externally_visible" attribute could be
+                #             a fix for that but it is not known to our LLVM.
+                LITEOS_COPTS_OPTMIZE = -Oz #-flto
+        else
+                LITEOS_COPTS_OPTMIZE = -Oz -flto
+        endif
     else
         LITEOS_COPTS_OPTMIZE = -O2
     endif