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/tegra124/display.c b/drivers/video/tegra124/display.c
index f834bd9..f642b3b 100644
--- a/drivers/video/tegra124/display.c
+++ b/drivers/video/tegra124/display.c
@@ -465,7 +465,7 @@
 
 static int tegra124_lcd_probe(struct udevice *dev)
 {
-	struct video_uc_platdata *plat = dev_get_uclass_plat(dev);
+	struct video_uc_plat *plat = dev_get_uclass_plat(dev);
 	ulong start;
 	int ret;
 
@@ -482,7 +482,7 @@
 
 static int tegra124_lcd_bind(struct udevice *dev)
 {
-	struct video_uc_platdata *uc_plat = dev_get_uclass_plat(dev);
+	struct video_uc_plat *uc_plat = dev_get_uclass_plat(dev);
 
 	uc_plat->size = LCD_MAX_WIDTH * LCD_MAX_HEIGHT *
 			(1 << VIDEO_BPP16) / 8;