drm/i915: make a few DDI functions static

We don't need to export them since they're not being used outside the
file. The next time I try to find the callers for these things I will
know I won't need to look outside intel_ddi.c.
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1490907472-10883-1-git-send-email-paulo.r.zanoni@intel.com

drivers/gpu/drm/i915/intel_ddi.c

@@ -539,7 +539,7 @@ intel_ddi_get_buf_trans_fdi(struct drm_i915_private *dev_priv,
  * values in advance. This function programs the correct values for
  * DP/eDP/FDI use cases.
  */
-void intel_prepare_dp_ddi_buffers(struct intel_encoder *encoder)
+static void intel_prepare_dp_ddi_buffers(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	u32 iboost_bit = 0;
@@ -806,7 +806,7 @@ void hsw_fdi_link_train(struct intel_crtc *crtc,
 		   DP_TP_CTL_ENABLE);
 }
 
-void intel_ddi_init_dp_buf_reg(struct intel_encoder *encoder)
+static void intel_ddi_init_dp_buf_reg(struct intel_encoder *encoder)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
 	struct intel_digital_port *intel_dig_port =
@@ -1616,7 +1616,7 @@ uint32_t ddi_signal_levels(struct intel_dp *intel_dp)
 	return DDI_BUF_TRANS_SELECT(level);
 }
 
-void intel_ddi_clk_select(struct intel_encoder *encoder,
+static void intel_ddi_clk_select(struct intel_encoder *encoder,
 				 struct intel_shared_dpll *pll)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);

drivers/gpu/drm/i915/intel_drv.h

@@ -1229,12 +1229,9 @@ void intel_crt_init(struct drm_i915_private *dev_priv);
 void intel_crt_reset(struct drm_encoder *encoder);
 
 /* intel_ddi.c */
-void intel_ddi_clk_select(struct intel_encoder *encoder,
-			  struct intel_shared_dpll *pll);
 void intel_ddi_fdi_post_disable(struct intel_encoder *intel_encoder,
 				struct intel_crtc_state *old_crtc_state,
 				struct drm_connector_state *old_conn_state);
-void intel_prepare_dp_ddi_buffers(struct intel_encoder *encoder);
 void hsw_fdi_link_train(struct intel_crtc *crtc,
 			const struct intel_crtc_state *crtc_state);
 void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port);
@@ -1255,7 +1252,6 @@ bool intel_ddi_is_audio_enabled(struct drm_i915_private *dev_priv,
 void intel_ddi_get_config(struct intel_encoder *encoder,
 			  struct intel_crtc_state *pipe_config);
 
-void intel_ddi_init_dp_buf_reg(struct intel_encoder *encoder);
 void intel_ddi_clock_get(struct intel_encoder *encoder,
 			 struct intel_crtc_state *pipe_config);
 void intel_ddi_set_vc_payload_alloc(const struct intel_crtc_state *crtc_state,