linux-wandboard

drm/i915: Check eDP power when doing aux channel communications

Verify that the eDP VDD is on, either with the panel being on or with
the VDD force-on bit being set.

This demonstrates that in many instances, VDD is not on when needed,
which leads to failed EDID communications.

Signed-off-by: Keith Packard <keithp@keithp.com>