This is required to move OP-TEE to upstream QEMU.

Signed-off-by: Victor Chong <victor.chong@linaro.org>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Victor Chong <victor.chong@linaro.org>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>