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/arch/arm/mach-stm32mp/bsec.c b/arch/arm/mach-stm32mp/bsec.c
index cb92089..a41824c 100644
--- a/arch/arm/mach-stm32mp/bsec.c
+++ b/arch/arm/mach-stm32mp/bsec.c
@@ -513,7 +513,7 @@
 	.id = UCLASS_MISC,
 	.of_match = stm32mp_bsec_ids,
 	.ofdata_to_platdata = stm32mp_bsec_ofdata_to_platdata,
-	.platdata_auto	= sizeof(struct stm32mp_bsec_platdata),
+	.plat_auto	= sizeof(struct stm32mp_bsec_platdata),
 	.ops = &stm32mp_bsec_ops,
 	.probe = stm32mp_bsec_probe,
 };