Revert "drm/i915/chv: Use timeout mode for RC6 on chv"

This reverts commit 5a0afd4b.

Although timeout mode allows higher residency it impact badly on performance.
I believe while we don't have a way to balance between performance and
power savings at runtime I believe we have to revert and prioritize
performance that was impacted a lot.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88103


Cc: Deepak S <deepak.s@linux.intel.com>
Cc: Wendy Wang <wendy.wang@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>