dm: treewide: Rename ..._platdata variables to just ..._plat

Try to maintain some consistency between these variables by using _plat as
a suffix for them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/efi.c b/drivers/video/efi.c
index ceb6f85..c248bd35 100644
--- a/drivers/video/efi.c
+++ b/drivers/video/efi.c
@@ -110,7 +110,7 @@
 
 static int efi_video_probe(struct udevice *dev)
 {
-	struct video_uc_platdata *plat = dev_get_uclass_plat(dev);
+	struct video_uc_plat *plat = dev_get_uclass_plat(dev);
 	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
 	struct vesa_mode_info *vesa = &mode_info.vesa;
 	int ret;