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/snps_dw_mmc.c b/drivers/mmc/snps_dw_mmc.c
index 009933d..0533bc2 100644
--- a/drivers/mmc/snps_dw_mmc.c
+++ b/drivers/mmc/snps_dw_mmc.c
@@ -196,5 +196,5 @@
 	.bind				= snps_dwmmc_bind,
 	.probe				= snps_dwmmc_probe,
 	.priv_auto		= sizeof(struct snps_dwmci_priv_data),
-	.platdata_auto	= sizeof(struct snps_dwmci_plat),
+	.plat_auto	= sizeof(struct snps_dwmci_plat),
 };