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/sti_sdhci.c b/drivers/mmc/sti_sdhci.c
index 49ddabc..1da569c 100644
--- a/drivers/mmc/sti_sdhci.c
+++ b/drivers/mmc/sti_sdhci.c
@@ -145,5 +145,5 @@
 	.ofdata_to_platdata = sti_sdhci_ofdata_to_platdata,
 	.probe = sti_sdhci_probe,
 	.priv_auto	= sizeof(struct sdhci_host),
-	.platdata_auto	= sizeof(struct sti_sdhci_plat),
+	.plat_auto	= sizeof(struct sti_sdhci_plat),
 };