drm/i915: Kill dp_encoder_is_mst

dp_encoder_is_mst flag in the crtc state can be replaced by
intel_crtc_has_type(..., INTEL_OUTPUT_DP_MST). Let's do that.

Cc: Maarten Lankhorst <[e-mail]>
Signed-off-by: Ville Syrjälä <[e-mail]>
Reviewed-by: Jim Bride <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/i915/intel_display.c

···
 	if (intel_crtc->config->has_pch_encoder)
 		lpt_pch_enable(crtc);
 
-	if (intel_crtc->config->dp_encoder_is_mst)
+	if (intel_crtc_has_type(intel_crtc->config, INTEL_OUTPUT_DP_MST))
 		intel_ddi_set_vc_payload_alloc(crtc, true);
 
 	assert_vblank_disabled(crtc);
···
 	if (!transcoder_is_dsi(cpu_transcoder))
 		intel_disable_pipe(intel_crtc);
 
-	if (intel_crtc->config->dp_encoder_is_mst)
+	if (intel_crtc_has_type(intel_crtc->config, INTEL_OUTPUT_DP_MST))
 		intel_ddi_set_vc_payload_alloc(crtc, false);
 
 	if (!transcoder_is_dsi(cpu_transcoder))

drivers/gpu/drm/i915/intel_dp_mst.c

···
 	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
 	int mst_pbn;
 
-	pipe_config->dp_encoder_is_mst = true;
 	pipe_config->has_pch_encoder = false;
 	bpp = 24;
 	/*

drivers/gpu/drm/i915/intel_drv.h

···
 
 	bool double_wide;
 
-	bool dp_encoder_is_mst;
 	int pbn;
 
 	struct intel_crtc_scaler_state scaler_state;