The memory ownership transfer request is performed using SCM, ensure
that SCM is available before we probe the driver if memory protection is
needed by the subsystem.

Fixes: 6c5a9dc2 ("remoteproc: qcom: Make secure world call for mem ownership switch")
Cc: stable@vger.kernel.org
Signed-off-by: Brian Norris <briannorris@chromium.org>
[bjorn: Added condition for need_mem_protection, updated commit message]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>