drm/nouveau/kms/nv50-: Remove nv50_mstc_best_encoder()

When drm_connector_helper_funcs->atomic_best_encoder is defined,
->best_encoder is ignored by the atomic modesetting helpers. That being
said, this hook is completely broken anyway - it always returns the
first msto for a given mstc, despite the fact it might already be in
use.

So, just get rid of it. We'll need this in a moment anyway, when we make
mstos per-head as opposed to per-connector.

Changes since v1:
* Fix typo in documentation - imirkin
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/dispnv50/disp.c

@@ -946,14 +946,6 @@ nv50_mstc_atomic_best_encoder(struct drm_connector *connector,
 	return &mstc->mstm->msto[head->base.index]->encoder;
 }
 
-static struct drm_encoder *
-nv50_mstc_best_encoder(struct drm_connector *connector)
-{
-	struct nv50_mstc *mstc = nv50_mstc(connector);
-
-	return &mstc->mstm->msto[0]->encoder;
-}
-
 static enum drm_mode_status
 nv50_mstc_mode_valid(struct drm_connector *connector,
 		     struct drm_display_mode *mode)
@@ -1038,7 +1030,6 @@ static const struct drm_connector_helper_funcs
 nv50_mstc_help = {
 	.get_modes = nv50_mstc_get_modes,
 	.mode_valid = nv50_mstc_mode_valid,
-	.best_encoder = nv50_mstc_best_encoder,
 	.atomic_best_encoder = nv50_mstc_atomic_best_encoder,
 	.atomic_check = nv50_mstc_atomic_check,
 	.detect_ctx = nv50_mstc_detect,