code: Add support for pmem non-temporal memcpy, memmove and memset

This pull request integrates the support for the PM versions of memset, memmove and memcpy using non-temporal instructions.
Right! My mistake!
I've been fooled by `d8` pointing to the address next to the last byte written. But due to alignment done in `pmem_flush`, the correct cache line (or page) will be flushed.