sna: Pass desired CRTC viewport for completing single CRTC flips

sna: Pass desired CRTC viewport for completing single CRTC flips

We cannot simply compare against the crtc->shadow_bo for all our needs,
so pass in exactly the setup we want and apply that. In particular this
is required when flipping away from the single CRTC setup on secondary
pipes.

Fixes TearFree multi-monitor regression from
commit 3932e97057fca16615adaefbc1eb25a0d51a1d8b [2.99.912]
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Mon Jun 9 08:58:15 2014 +0100

    sna/dri2: Allow TearFree flipping to individual CRTC

Reported-by: Leo Wolf <jclw@ymail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80191