drm/i915: TVDAC_STATE_CHG does not indicate successful load-detect

Do not use this bit to indicate that load detection has completed,
instead just wait for vblank, at which point the load registers will
have been updated.

Signed-off-by: Keith Packard <keithp@keithp.com>
Tested-by: Yi Sun <yi.sun@intel.com>
1 file changed