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/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
index 12e8c99..7490e86 100644
--- a/drivers/mmc/sunxi_mmc.c
+++ b/drivers/mmc/sunxi_mmc.c
@@ -746,7 +746,7 @@
 	.bind		= sunxi_mmc_bind,
 	.probe		= sunxi_mmc_probe,
 	.ops		= &sunxi_mmc_ops,
-	.platdata_auto	= sizeof(struct sunxi_mmc_plat),
+	.plat_auto	= sizeof(struct sunxi_mmc_plat),
 	.priv_auto	= sizeof(struct sunxi_mmc_priv),
 };
 #endif