dm: treewide: Rename 'platdata' variables to just 'plat'

We use 'priv' for private data but often use 'platdata' for platform data.
We can't really use 'pdata' since that is ambiguous (it could mean private
or platform data).

Rename some of the latter variables to end with 'plat' for consistency.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/led/led_gpio.c b/drivers/led/led_gpio.c
index fe18ae3..67ece3c 100644
--- a/drivers/led/led_gpio.c
+++ b/drivers/led/led_gpio.c
@@ -57,7 +57,7 @@
 
 static int led_gpio_probe(struct udevice *dev)
 {
-	struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
+	struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
 	struct led_gpio_priv *priv = dev_get_priv(dev);
 	int ret;
 
@@ -106,7 +106,7 @@
 						 node, &dev);
 		if (ret)
 			return ret;
-		uc_plat = dev_get_uclass_platdata(dev);
+		uc_plat = dev_get_uclass_plat(dev);
 		uc_plat->label = label;
 	}