[REPOST PATCH 1/2] Add CRTC ID to vblank events

[Daniel Stone]

Hi,
Following the annual tradition, I've rebased Ander/Maarten's patches
to include the CRTC ID in vblank events. Specifically, this makes it
possible to know which CRTC an atomic request-completion event refers
to.

I'm using this in Weston, for which I can ack it as good API, and a
second opinion of this should be on the way shortly.

Cheers,
Daniel