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/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index fb9393d..fdb3a45 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -341,7 +341,7 @@
 	.ofdata_to_platdata = gpio_hog_ofdata_to_platdata,
 	.probe = gpio_hog_probe,
 	.priv_auto	= sizeof(struct gpio_hog_priv),
-	.platdata_auto	= sizeof(struct gpio_hog_data),
+	.plat_auto	= sizeof(struct gpio_hog_data),
 };
 #else
 int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc)