qemu_v8: fix build error with SPMC_AT_EL=2

The git command used to checkout the submodules in the Hafnium
repository is wrong. Fix it.

Fixes: e9290f81f9a4 ("qemu_v8: add support for Hafnium as S-EL2")
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/qemu_v8.mk b/qemu_v8.mk
index 43e52f2..618097f 100644
--- a/qemu_v8.mk
+++ b/qemu_v8.mk
@@ -403,7 +403,7 @@
 HAFNIUM_EXPORTS = PATH=$(HAFNIUM_PATH)/prebuilts/linux-x64/clang/bin:$(HAFNIUM_PATH)/prebuilts/linux-x64/dtc:$(PATH)
 
 .hafnium_checkout:
-	git -C $(HAFNIUM_PATH) submodule init --update
+	git -C $(HAFNIUM_PATH) submodule update --init
 	touch $@
 
 hafnium: $(HAFNIUM_BIN)