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/net/dwmac_s700.c b/drivers/net/dwmac_s700.c
index 2edd7a7..adb865d 100644
--- a/drivers/net/dwmac_s700.c
+++ b/drivers/net/dwmac_s700.c
@@ -62,6 +62,6 @@
 	.probe  = dwmac_s700_probe,
 	.ops    = &designware_eth_ops,
 	.priv_auto	= sizeof(struct dw_eth_dev),
-	.platdata_auto	= sizeof(struct eth_pdata),
+	.plat_auto	= sizeof(struct eth_pdata),
 	.flags = DM_FLAG_ALLOC_PRIV_DMA,
 };