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/power/domain/imx8m-power-domain.c b/drivers/power/domain/imx8m-power-domain.c
index 3736019..7e2d232 100644
--- a/drivers/power/domain/imx8m-power-domain.c
+++ b/drivers/power/domain/imx8m-power-domain.c
@@ -137,6 +137,6 @@
 	.bind = imx8m_power_domain_bind,
 	.probe = imx8m_power_domain_probe,
 	.ofdata_to_platdata = imx8m_power_domain_ofdata_to_platdata,
-	.platdata_auto	= sizeof(struct imx8m_power_domain_platdata),
+	.plat_auto	= sizeof(struct imx8m_power_domain_platdata),
 	.ops = &imx8m_power_domain_ops,
 };