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/usb/host/ehci-zynq.c b/drivers/usb/host/ehci-zynq.c
index 738eed3..df7ea0a 100644
--- a/drivers/usb/host/ehci-zynq.c
+++ b/drivers/usb/host/ehci-zynq.c
@@ -85,7 +85,7 @@
 	.probe = ehci_zynq_probe,
 	.remove = ehci_deregister,
 	.ops	= &ehci_usb_ops,
-	.platdata_auto	= sizeof(struct usb_platdata),
+	.plat_auto	= sizeof(struct usb_platdata),
 	.priv_auto	= sizeof(struct zynq_ehci_priv),
 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
 };