drm/i915: create functions for the "unclaimed register" checks

This avoids polluting i915_write##x and also allows us to reuse code
on i915_read##x.

v2: Rebase
v3: Convert the macros to static functions

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
1 file changed