generic ioremap (and lots of cleanups) v2

[Christoph Hellwig]

Hi all,

the last patches in this series add a generic ioremap implementation,
and switch our 3 most recent and thus most tidy architeture ports over
to use it.  With a little work and an additional arch hook or two the
implementation should be able to eventually cover more than half of
our ports.

The patches before that clean up various lose ends in the ioremap
and iounmap implementations.

A git tree is also available here:

    git://git.infradead.org/users/hch/misc.git generic-ioremap

Gitweb:

    http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/generic-ioremap

Changes since v1:
 - dropped various patches already merged
 - keep the parts of the parisc EISA hack that are still needed