MIPS: Use phys_addr_t instead of phys_t

Ralf Baechle says:
 "This should have been part of the merge commit c0222ac0 (Merge
  branch 'upstream' of git://git.linux-mips.org/pub/scm/-


  ralf/upstream-linus) but I forgot to mention the need for this in my
  pull request"

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>