[drm pull] single intel fix for SNB irqs

Hi Linus This is a workaround for lost IRQs on the SNB platform that causes stalls in rendering, by all reports it actually seems to work, so until the hw guys explain things better, we'll go with it. Dave. The following changes since commit 95d17b7168eacf1f97f2d1d087ebe7a648c30051: Merge

[drm pull] single intel fix for SNB irqs

Hi Linus This is a workaround for lost IRQs on the SNB platform that causes stalls in rendering, by all reports it actually seems to work, so until the hw guys explain things better, we'll go with it. Dave. The following changes since commit 95d17b7168eacf1f97f2d1d087ebe7a648c30051: Merge