hikey960: use current GCC instead of legacy toolchain

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

hikey960.mk

@@ -110,7 +110,7 @@ ifeq ($(CFG_CONSOLE_UART),5)
 endif
 
 define edk2-call
-	$(EDK2_TOOLCHAIN)_$(EDK2_ARCH)_PREFIX=$(LEGACY_AARCH64_CROSS_COMPILE) \
+	$(EDK2_TOOLCHAIN)_$(EDK2_ARCH)_PREFIX=$(AARCH64_CROSS_COMPILE) \
 	build -n `getconf _NPROCESSORS_ONLN` -a $(EDK2_ARCH) \
 		-t $(EDK2_TOOLCHAIN) -p $(EDK2_DSC) \
 		-b $(EDK2_BUILD) $(EDK2_BUILDFLAGS)