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/ks8851_mll.c b/drivers/net/ks8851_mll.c
index 6340d63..b0e6685 100644
--- a/drivers/net/ks8851_mll.c
+++ b/drivers/net/ks8851_mll.c
@@ -699,7 +699,7 @@
 	.probe		= ks8851_probe,
 	.ops		= &ks8851_ops,
 	.priv_auto	= sizeof(struct ks_net),
-	.platdata_auto	= sizeof(struct eth_pdata),
+	.plat_auto	= sizeof(struct eth_pdata),
 	.flags		= DM_FLAG_ALLOC_PRIV_DMA,
 };
 #endif