Switch to {xtest,optee-examples}-clean-common

Switches to xtest-clean-common optee-examples-clean-common instead of
xtest-clean optee-examples-clean in the optee-os-clean-common. This is
needed in case the platform make file doesn't provide these targets.

Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

common.mk

@@ -306,7 +306,7 @@ OPTEE_OS_CLEAN_COMMON_FLAGS ?= $(OPTEE_OS_COMMON_EXTRA_FLAGS)
 ifeq ($(CFG_TEE_BENCHMARK),y)
 optee-os-clean-common: benchmark-app-clean-common
 endif
-optee-os-clean-common: xtest-clean optee-examples-clean
+optee-os-clean-common: xtest-clean-common optee-examples-clean-common
 	$(MAKE) -C $(OPTEE_OS_PATH) $(OPTEE_OS_CLEAN_COMMON_FLAGS) clean
 
 OPTEE_CLIENT_COMMON_FLAGS ?= CROSS_COMPILE=$(CROSS_COMPILE_NS_USER) \