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/sdhci-cadence.c b/drivers/mmc/sdhci-cadence.c
index efc09b9..ffbac44 100644
--- a/drivers/mmc/sdhci-cadence.c
+++ b/drivers/mmc/sdhci-cadence.c
@@ -310,6 +310,6 @@
 	.bind = sdhci_cdns_bind,
 	.probe = sdhci_cdns_probe,
 	.priv_auto	= sizeof(struct sdhci_host),
-	.platdata_auto	= sizeof(struct sdhci_cdns_plat),
+	.plat_auto	= sizeof(struct sdhci_cdns_plat),
 	.ops = &sdhci_cdns_mmc_ops,
 };