MFC r339559,344083,344202,344203,344204

Bulk merge of Book-E pmap changes

r339559: powerpc/booke: Turn tlb*_print_tlbentries() into 'show tlb*' DDB
commands
r344083: powerpc/booke: Use the 'tlbilx' instruction on newer cores
r344202,344204: powerpc/booke: Use DMAP where possible for page copy and zeroing
r344203: powerpc/booke: depessimize MAS register updates