Persistent mapping of some VTL0/normal-world physical addresses

[sangho2]

Currently, the LVBS platform and OP-TEE map VTL0/normal-world physical addresses on demand to simplify memory-safe access to them. In some use cases (i.e., append-only logging), this is just bad for performance without any safety benefit (VTL1/secure-world do not read data from those addresses).

#808

[sangho2]

ProtectedFrameRegistry now ensures that ordinary PhysMutPtr cannot access write-protected frames which include the log ring buffer. Also, this does not result in Rust safety/soundness issues anyhow (pure write. no read back). In that sense, having this persistent mapping is reasonable and also good for dealing with panic logging (no extra allocation/mapping is needed to log messages).