It's for legacy drivers, for atomic drivers crtc->state->encoder_mask
should be used to map encoder to crtc.

Changes in v2:
- None
Reviewed-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
[seanpaul resolved conflict with async param of dpu_encoder_kickoff]
Signed-off-by: Rob Clark <robdclark@gmail.com>