m32r: fix pte_to_pgoff(), pgoff_to_pte() and __swp_type() macros

m32r: fix pte_to_pgoff(), pgoff_to_pte() and __swp_type() macros

This patch is required to handle file-mapped or swapped-out pages
correctly.

- Fix pte_to_pgoff() and pgoff_to_pte() macros not to include
  _PAGE_PROTNONE bit of PTE.
  Mask value for { ACCESSED, N, (R, W, X), L, G } is not 0xef but 0x7f.
- Fix __swp_type() macro for MAX_SWAPFILES_SHIFT(=5), which is defined
  in include/linux/swap.h.

* M32R TLB format

     [0]    [1:19]           [20:23]       [24:31]
     +-----------------------+----+-------------+
     |          VPN          |0000|    ASID     |
     +-----------------------+----+-------------+
     +-+---------------------+----+-+---+-+-+-+-+
     |0         PPN          |0000|N|AC |L|G|V| |
     +-+---------------------+----+-+---+-+-+-+-+
                                ||   RWX     | |
* software bits in PTE          ||           | +-- _PAGE_FILE | _PAGE_DIRTY
                                ||           +---- _PAGE_PRESENT
                                |+---------------- _PAGE_ACCESSED
                                +----------------- _PAGE_PROTNONE

Signed-off-by: Hitoshi Yamamoto <hitoshiy@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>