[PATCH] headers: add i915-perf interface to i915_drm.h

[Emil Velikov]

Hi Robert

Just a couple of trivial suggestions:
 - git config --local format.subjectPrefix "PATCH libdrm"
 - make sure that the headers are generated via `make headers_install'
and state the tree/sha that you've used.
See 9af2ccdef cc9a53f07 or 89cdda3d5.

Thanks
Emil
P.S. /me goes to add a README with the above instructions