remoteproc: qcom_q6v5_mss: Use a carveout to authenticate modem headers

remoteproc: qcom_q6v5_mss: Use a carveout to authenticate modem headers

Any access to the dynamically allocated metadata region by the application
processor after assigning it to the remote Q6 will result in a XPU
violation. Fix this by replacing the dynamically allocated memory region
with a no-map carveout and unmap the modem metadata memory region before
passing control to the remote Q6.

Reported-and-tested-by: Amit Pundir <[email protected]>
Fixes: 6c5a9dc2481b ("remoteproc: qcom: Make secure world call for mem ownership switch")
Signed-off-by: Sibi Sankar <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]