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/vybrid_gpio.c b/drivers/gpio/vybrid_gpio.c
index 9c4bba8..f55553c 100644
--- a/drivers/gpio/vybrid_gpio.c
+++ b/drivers/gpio/vybrid_gpio.c
@@ -133,5 +133,5 @@
 	.ofdata_to_platdata = vybrid_gpio_odata_to_platdata,
 	.probe	= vybrid_gpio_probe,
 	.priv_auto	= sizeof(struct vybrid_gpios),
-	.platdata_auto	= sizeof(struct vybrid_gpio_platdata),
+	.plat_auto	= sizeof(struct vybrid_gpio_platdata),
 };