drm/i915: Track has_audio in the pipe config

Including state readout and cross-checking. This allows us to get rid
of crtc->eld_vld on hsw+. It also means that fastboot will be unhappy
if the BIOS hasn't set up the audio routing like we want it too.

Wrt fastboot and external screens I see a few options:
- Don't.
- Try to fix up eld, infoframes and audio settings after the fact. But
  that means some pretty extensive reworking of our code which
  currently does all this while the pipe/port is still off.

I won't bother with converting SDVO over to this because the audio
support for SDVO is very lacking:
- We don't update the eld.
- We don't update the audio state on the sdvo encoder.
- We don't check whether the platform can even feed audio to the sdvo
  encoder.

I've converted hdmi, dp & ddi all in one go since ddi needs both hdmi
and dp converted and so doing it step-by-step would have required a
few intermediate hacks.

Reviewed-by: Naresh Kumar Kachhi <naresh.kumar.kachhi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3a5b2ed..93742ae 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4690,13 +4690,11 @@
 	struct drm_device *dev = crtc->dev;
 	struct drm_connector *connector;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 
 	/* crtc should still be enabled when we disable it. */
 	WARN_ON(!crtc->enabled);
 
 	dev_priv->display.crtc_disable(crtc);
-	intel_crtc->eld_vld = false;
 	intel_crtc_update_sarea(crtc, false);
 	dev_priv->display.off(crtc);
 
@@ -7619,7 +7617,6 @@
 {
 	struct drm_i915_private *dev_priv = connector->dev->dev_private;
 	uint8_t *eld = connector->eld;
-	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	uint32_t eldv;
 	uint32_t i;
 	int len;
@@ -7658,7 +7655,6 @@
 	DRM_DEBUG_DRIVER("ELD on pipe %c\n", pipe_name(pipe));
 
 	eldv = AUDIO_ELD_VALID_A << (pipe * 4);
-	intel_crtc->eld_vld = true;
 
 	if (intel_pipe_has_type(crtc, INTEL_OUTPUT_DISPLAYPORT)) {
 		DRM_DEBUG_DRIVER("ELD: DisplayPort detected\n");
@@ -9894,6 +9890,8 @@
 	    IS_VALLEYVIEW(dev))
 		PIPE_CONF_CHECK_I(limited_color_range);
 
+	PIPE_CONF_CHECK_I(has_audio);
+
 	PIPE_CONF_CHECK_FLAGS(adjusted_mode.flags,
 			      DRM_MODE_FLAG_INTERLACE);