drm: bridge: analogix/dp: mark symbols static where possible

We get 2 warnings when building kernel with W=1:
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c:1053:5: warning: no previous prototype for 'analogix_dp_get_modes' [-Wmissing-prototypes]
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c:1097:1: warning: no previous prototype for 'analogix_dp_detect' [-Wmissing-prototypes]

In fact, both functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
So this patch marks both functions with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474788764-6069-1-git-send-email-baoyou.xie@linaro.org

drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

@@ -918,7 +918,7 @@ static int analogix_dp_prepare_panel(struct analogix_dp_device *dp,
 	return ret;
 }
 
-int analogix_dp_get_modes(struct drm_connector *connector)
+static int analogix_dp_get_modes(struct drm_connector *connector)
 {
 	struct analogix_dp_device *dp = to_dp(connector);
 	struct edid *edid;
@@ -965,7 +965,7 @@ static const struct drm_connector_helper_funcs analogix_dp_connector_helper_func
 	.best_encoder = analogix_dp_best_encoder,
 };
 
-enum drm_connector_status
+static enum drm_connector_status
 analogix_dp_detect(struct drm_connector *connector, bool force)
 {
 	struct analogix_dp_device *dp = to_dp(connector);