M68k core mm updates
  - Update fault handling
  - Remove superfluous flush_tlb_page()
  - Remove obsolete comment
  - empty_zero_page becomes a void *
  - Type and cast clean ups
  - Remove duplicated test for voff == 0
  - Move check_pgt_cache() to pgtable.h
  - Pte and pmd updates
  - Add additional parameter to {clear,copy}_user_page()
  - pfn updates
  - BUG() updates
  - Move check_pgt_cache() from motorola_pgalloc.h
  - Misc updates
  - Add __page_address() and page_to_phys()