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/am654_sdhci.c b/drivers/mmc/am654_sdhci.c
index 926fba6..2015e31 100644
--- a/drivers/mmc/am654_sdhci.c
+++ b/drivers/mmc/am654_sdhci.c
@@ -495,5 +495,5 @@
 	.bind		= am654_sdhci_bind,
 	.probe		= am654_sdhci_probe,
 	.priv_auto	= sizeof(struct sdhci_host),
-	.platdata_auto	= sizeof(struct am654_sdhci_plat),
+	.plat_auto	= sizeof(struct am654_sdhci_plat),
 };