a) every bitwise declaration will give a unique type; use typedefs.

 b) no need to bother with the stuff pointed to by iomem pointers,
    unless it's accessed directly.  noderef will force us to use helpers
    anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>