drm/i915: Move the encoder vs. FDI dotclock check out from encoder .get_config()

Currently we check if the encoder's idea of dotclock agrees with what
we calculated based on the FDI parameters. We do this in the encoder
.get_config() hooks, which isn't so nice in case the BIOS (or some other
outside party) made a mess of the state and we're just trying to take
over.

So as a prep step to being able sanitize such a bogus state, move the
the sanity check to just after we've read out the entire state. If
we then need to sanitize a bad state, it should be easier to move the
sanity check to occur after sanitation instead of before it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455738073-14502-3-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

drivers/gpu/drm/i915/intel_lvds.c

@@ -109,7 +109,6 @@ static void intel_lvds_get_config(struct intel_encoder *encoder,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
 	u32 tmp, flags = 0;
-	int dotclock;
 
 	tmp = I915_READ(lvds_encoder->reg);
 	if (tmp & LVDS_HSYNC_POLARITY)
@@ -130,12 +129,7 @@ static void intel_lvds_get_config(struct intel_encoder *encoder,
 		pipe_config->gmch_pfit.control |= tmp & PANEL_8TO6_DITHER_ENABLE;
 	}
 
-	dotclock = pipe_config->port_clock;
-
-	if (HAS_PCH_SPLIT(dev_priv->dev))
-		ironlake_check_encoder_dotclock(pipe_config, dotclock);
-
-	pipe_config->base.adjusted_mode.crtc_clock = dotclock;
+	pipe_config->base.adjusted_mode.crtc_clock = pipe_config->port_clock;
 }
 
 static void intel_pre_enable_lvds(struct intel_encoder *encoder)