linux-phytec-ti

drm/i915: Update comment in clear_intel_crtc_state()

Explain why a few fields of the new pipe_config have their values
preserved, while the others are zeroed.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>