drm/i915: Use pipe_config's cpu_transcoder for reading encoder hw state

The get_config() functions for ddi and dp_mst, used to read the value
of cpu_transcoder from the crtc->config instead of the state passed as
an argument. On the hardware state readout path, that happens to work
since the proper value is written to it before encoder->get_config() is
called. However, in the check_crtc() path, the state will be read from
the cpu_transcoder in the software tracking, instead of the one just
read out from hw. Using the field in the supplied intel_crtc_state
should do the right thing in both cases.

v2: Fix intel_ddi_get_config() too. (Ander)
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_ddi.c

@@ -2038,7 +2038,7 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
 {
 	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
-	enum transcoder cpu_transcoder = intel_crtc->config->cpu_transcoder;
+	enum transcoder cpu_transcoder = pipe_config->cpu_transcoder;
 	struct intel_hdmi *intel_hdmi;
 	u32 temp, flags = 0;
 

drivers/gpu/drm/i915/intel_dp_mst.c

@@ -226,7 +226,7 @@ static void intel_dp_mst_enc_get_config(struct intel_encoder *encoder,
 	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
 	struct drm_device *dev = encoder->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	enum transcoder cpu_transcoder = crtc->config->cpu_transcoder;
+	enum transcoder cpu_transcoder = pipe_config->cpu_transcoder;
 	u32 temp, flags = 0;
 
 	pipe_config->has_dp_encoder = true;