drm/i915: mark dumb gem objects

Signed-off-by: Imre Deak <imre.deak@intel.com>
drm/i915: factor out set_gtt_domain

Signed-off-by: Imre Deak <imre.deak@intel.com>
drm/i915: no need to mark fb as busy at execbuf time

We need to switch to higher PLL rate, disable FBC, etc. only at the next
page flip and at that time we mark the FB busy already. So no need to do
it here.

Signed-off-by: Imre Deak <imre.deak@intel.com>
drm/i915: don't allow FBC if the FB is in GTT write domain

Signed-off-by: Imre Deak <imre.deak@intel.com>
drm/i915: mark_fb_busy in set_to_gtt_domain

Signed-off-by: Imre Deak <imre.deak@intel.com>
drm/i915: disable fbc from intel_mark_fb_busy

Signed-off-by: Imre Deak <imre.deak@intel.com>