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/pci/pci-rcar-gen3.c b/drivers/pci/pci-rcar-gen3.c
index f01fcf6..3a0a4b5 100644
--- a/drivers/pci/pci-rcar-gen3.c
+++ b/drivers/pci/pci-rcar-gen3.c
@@ -400,5 +400,5 @@
 	.ops			= &rcar_gen3_pcie_ops,
 	.probe			= rcar_gen3_pcie_probe,
 	.ofdata_to_platdata	= rcar_gen3_pcie_ofdata_to_platdata,
-	.platdata_auto	= sizeof(struct rcar_gen3_pcie_priv),
+	.plat_auto	= sizeof(struct rcar_gen3_pcie_priv),
 };