Add a 20MB reserved memory region for use by SCM calls.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20240527-shm-bridge-v10-15-ce7afaa58d3a@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>