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/common/lcd_simplefb.c b/common/lcd_simplefb.c
index 9cf1668..246eb4c 100644
--- a/common/lcd_simplefb.c
+++ b/common/lcd_simplefb.c
@@ -22,7 +22,7 @@
 	const char *name;
 	ulong fb_base;
 #ifdef CONFIG_DM_VIDEO
-	struct video_uc_platdata *plat;
+	struct video_uc_plat *plat;
 	struct video_priv *uc_priv;
 	struct udevice *dev;
 	int ret;