drm/bochs: mark bochs_connector_get_modes() static

We get 1 warning when building kernel with W=1:
drivers/gpu/drm/bochs/bochs_kms.c:181:5: warning: no previous prototype for 'bochs_connector_get_modes' [-Wmissing-prototypes]

In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
So this patch marks it 'static'.
Signed-off-by: NBaoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474788334-11007-1-git-send-email-baoyou.xie@linaro.org

drivers/gpu/drm/bochs/bochs_kms.c

@@ -178,7 +178,7 @@ static void bochs_encoder_init(struct drm_device *dev)
 }
 
 
-int bochs_connector_get_modes(struct drm_connector *connector)
+static int bochs_connector_get_modes(struct drm_connector *connector)
 {
 	int count;