drm/i915: Do DRRS disable/enable during pre/post_plane_update()

Let's just do a full DRRS disable/enable across all pipe updates.
This guarantees that the DRRS work doesn't interfere with anything
while the atomic commit is busy reprogramming the pipe.

Needed so that we can start reprogramming M/N seamlessly during
fastsets whenever possible. Also avoids the pre-bdw DRRS PIPECONF
rmw racing with the potential PIPECONF write from the atomic
commit (eg. due to GAMMA_MODE changes).

v2: Include has_drrs in state dump (José)

Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220315213944.17132-1-ville.syrjala@linux.intel.com