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/bcmstb_sdhci.c b/drivers/mmc/bcmstb_sdhci.c
index a92467f..e8041eb 100644
--- a/drivers/mmc/bcmstb_sdhci.c
+++ b/drivers/mmc/bcmstb_sdhci.c
@@ -101,5 +101,5 @@
 	.bind = sdhci_bcmstb_bind,
 	.probe = sdhci_bcmstb_probe,
 	.priv_auto	= sizeof(struct sdhci_host),
-	.platdata_auto	= sizeof(struct sdhci_bcmstb_plat),
+	.plat_auto	= sizeof(struct sdhci_bcmstb_plat),
 };