drm/i915: Split DP/eDP/FDI and HDMI/DVI DDI buffer programming apart

DDI buffer prorgramming works quite differently depending on
the mode of the DDI port (DP/eDP/FDI vs. HDMI/DVI). Let's split
the function that does the programming into two matching variants
as well.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1468328376-6380-7-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index e74d851..50cdc89 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1107,7 +1107,7 @@
 /* intel_ddi.c */
 void intel_ddi_clk_select(struct intel_encoder *encoder,
 			  const struct intel_crtc_state *pipe_config);
-void intel_prepare_ddi_buffer(struct intel_encoder *encoder);
+void intel_prepare_dp_ddi_buffers(struct intel_encoder *encoder);
 void hsw_fdi_link_train(struct drm_crtc *crtc);
 void intel_ddi_init(struct drm_device *dev, enum port port);
 enum port intel_ddi_get_encoder_port(struct intel_encoder *intel_encoder);