drm/sti: fix build warnings in sti_drv.c and sti_vtg.c files

Fix compilation warning introduced by:
commit 0c7ff84f7f ("drm/sti: remove deprecated legacy vtg slave")
commit 5e60f595d6 ("drm/sti: use atomic_helper for commit")

Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/sti/sti_drv.c

@@ -117,15 +117,6 @@ err:
 	return ret;
 }
 
-static void sti_drm_dbg_cleanup(struct drm_minor *minor)
-{
-	drm_debugfs_remove_files(sti_drm_dbg_list,
-				 ARRAY_SIZE(sti_drm_dbg_list), minor);
-
-	drm_debugfs_remove_files((struct drm_info_list *)&sti_drm_fps_fops,
-				 1, minor);
-}
-
 static int sti_atomic_check(struct drm_device *dev,
 			    struct drm_atomic_state *state)
 {

drivers/gpu/drm/sti/sti_vtg.c

@@ -389,7 +389,6 @@ static irqreturn_t vtg_irq(int irq, void *arg)
 static int vtg_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct device_node *np;
 	struct sti_vtg *vtg;
 	struct resource *res;
 	int ret;