drm/radeon/dp: make radeon_dp_get_dp_link_config static

It's not used outside this file any longer.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/atombios_dp.c

@@ -304,7 +304,7 @@ static int convert_bpc_to_bpp(int bpc)
 
 /***** radeon specific DP functions *****/
 
-int radeon_dp_get_dp_link_config(struct drm_connector *connector,
+static int radeon_dp_get_dp_link_config(struct drm_connector *connector,
 					const u8 dpcd[DP_DPCD_SIZE],
 					unsigned pix_clock,
 					unsigned *dp_lanes, unsigned *dp_rate)

drivers/gpu/drm/radeon/radeon_mode.h

@@ -762,10 +762,6 @@ extern u8 radeon_dp_getsinktype(struct radeon_connector *radeon_connector);
 extern bool radeon_dp_getdpcd(struct radeon_connector *radeon_connector);
 extern int radeon_dp_get_panel_mode(struct drm_encoder *encoder,
 				    struct drm_connector *connector);
-extern int radeon_dp_get_dp_link_config(struct drm_connector *connector,
-					const u8 *dpcd,
-					unsigned pix_clock,
-					unsigned *dp_lanes, unsigned *dp_rate);
 extern void radeon_dp_set_rx_power_state(struct drm_connector *connector,
 					 u8 power_state);
 extern void radeon_dp_aux_init(struct radeon_connector *radeon_connector);