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/clk/clk_boston.c b/drivers/clk/clk_boston.c
index 99edaec..75e2e43 100644
--- a/drivers/clk/clk_boston.c
+++ b/drivers/clk/clk_boston.c
@@ -92,6 +92,6 @@
 	.id = UCLASS_CLK,
 	.of_match = clk_boston_match,
 	.ofdata_to_platdata = clk_boston_ofdata_to_platdata,
-	.platdata_auto	= sizeof(struct clk_boston),
+	.plat_auto	= sizeof(struct clk_boston),
 	.ops = &clk_boston_ops,
 };