Ensure that the pc-bios/optionrom and pc-bios/s390-ccw directory
exist at the time when we'll write out the compiler configuration
for them.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220517092616.1272238-13-pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220527153603.887929-24-alex.bennee@linaro.org>