ST remote processor needs some specified memory regions for
firmware and IPC.
Memory regions are defined as reserved memory and should
be registered in remoteproc core thanks to rproc_add_carveout
function before rproc_start. For this, st rproc driver implements
prepare ops.
Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>