drm/i915: [sparse] __iomem fixes for opregion

Almost all of the errors related __iomem problems.

Most of the changes here are trivial, however there is plenty of chance
for yank/paste errors.

Signed-off-by: Ben Widawsky <benjamin.widawsky@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>