drm/i915: rip out legacy encoder->mode_set callback
drm/i915: rip out legacy encoder->mode_set callback

The encoder->mode_set callback from the crtc helpers is now completely
unused in our driver. Good riddance!

Reviewed-by: Rodrigo Vivi <f714145d6ee82178e54021e0c168f56d17b53c9c@gmail.com>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs