drm/i915: move intel_dp_set_m_n() to encoder for DDI platforms

intel_dp_set_m_n() has a clear place in the DDI DP specific pre-enable
hook.

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128162850.8660-3-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -3583,6 +3583,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
 	 */
 	if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST))
 		intel_ddi_set_dp_msa(crtc_state, conn_state);
+
+	intel_dp_set_m_n(crtc_state, M1_N1);
 }
 
 static void intel_ddi_pre_enable_hdmi(struct intel_encoder *encoder,

drivers/gpu/drm/i915/display/intel_display.c

@@ -6977,9 +6977,6 @@ static void hsw_crtc_enable(struct intel_atomic_state *state,
 
 	intel_encoders_pre_enable(state, crtc);
 
-	if (intel_crtc_has_dp_encoder(new_crtc_state))
-		intel_dp_set_m_n(new_crtc_state, M1_N1);
-
 	if (!transcoder_is_dsi(cpu_transcoder))
 		intel_set_pipe_timings(new_crtc_state);