Persistent mapping of some VTL0/normal-world physical addresses

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

Start by tracing how the LVBS platform and OP-TEE currently map VTL0/normal-world physical addresses on demand. Determine where persistent mappings could fit for append-only logging, then verify that repeated mapping overhead is avoided without changing the stated safety assumptions.

Written by the indexing model from the issue text.