- Remove the now unused CPU_NAND_ATOMIC() - Add a comment explaining that CPU_OR_ATOMIC() and   CPU_COPY_STORE_REL() are special wrappers used to cater particular   cases.
- Remove the now unused CPU_NAND_ATOMIC()
- Add a comment explaining that CPU_OR_ATOMIC() and
  CPU_COPY_STORE_REL() are special wrappers used to cater particular
  cases.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase