drm/i915/dg2: configure TRANS_DP2_VFREQ{HIGH,LOW} for 128b/132b

There's a new register pair for 128b/132b mode where you need to set the
pixel clock in Hz.

v2: Fix UHBR rate check, use intel_dp_is_uhbr() helper

Bspec: 54128
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a2902cc188973f022f282f2a77e693afdecefb5a.1631191763.git.jani.nikula@intel.com

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

@@ -550,6 +550,17 @@ static void intel_mst_enable_dp(struct intel_atomic_state *state,
 
 	clear_act_sent(encoder, pipe_config);
 
+	if (intel_dp_is_uhbr(pipe_config)) {
+		const struct drm_display_mode *adjusted_mode =
+			&pipe_config->hw.adjusted_mode;
+		u64 crtc_clock_hz = KHz(adjusted_mode->crtc_clock);
+
+		intel_de_write(dev_priv, TRANS_DP2_VFREQHIGH(pipe_config->cpu_transcoder),
+			       TRANS_DP2_VFREQ_PIXEL_CLOCK(crtc_clock_hz >> 24));
+		intel_de_write(dev_priv, TRANS_DP2_VFREQLOW(pipe_config->cpu_transcoder),
+			       TRANS_DP2_VFREQ_PIXEL_CLOCK(crtc_clock_hz & 0xffffff));
+	}
+
 	intel_ddi_enable_transcoder_func(encoder, pipe_config);
 
 	intel_de_rmw(dev_priv, TRANS_DDI_FUNC_CTL(trans), 0,