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/mtd/spi/sandbox.c b/drivers/mtd/spi/sandbox.c
index f52295a..26d0dbc 100644
--- a/drivers/mtd/spi/sandbox.c
+++ b/drivers/mtd/spi/sandbox.c
@@ -138,7 +138,7 @@
 			dev->name);
 		return ret;
 	}
-	slave_plat = dev_get_parent_platdata(dev);
+	slave_plat = dev_get_parent_plat(dev);
 	cs = slave_plat->cs;
 	debug("found at cs %d\n", cs);
 
@@ -601,6 +601,6 @@
 	.probe		= sandbox_sf_probe,
 	.remove		= sandbox_sf_remove,
 	.priv_auto	= sizeof(struct sandbox_spi_flash),
-	.platdata_auto	= sizeof(struct sandbox_spi_flash_plat_data),
+	.plat_auto	= sizeof(struct sandbox_spi_flash_plat_data),
 	.ops		= &sandbox_sf_emul_ops,
 };