dm: treewide: Rename ..._platdata variables to just ..._plat

Try to maintain some consistency between these variables by using _plat as
a suffix for them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/lib/sfi.c b/arch/x86/lib/sfi.c
index 7de0aa0..85e963b 100644
--- a/arch/x86/lib/sfi.c
+++ b/arch/x86/lib/sfi.c
@@ -84,7 +84,7 @@
 	for (uclass_find_first_device(UCLASS_CPU, &dev);
 	     dev;
 	     uclass_find_next_device(&dev)) {
-		struct cpu_platdata *plat = dev_get_parent_plat(dev);
+		struct cpu_plat *plat = dev_get_parent_plat(dev);
 
 		if (!device_active(dev))
 			continue;