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/include/video.h b/include/video.h
index 9d09d24..31a12bd 100644
--- a/include/video.h
+++ b/include/video.h
@@ -21,7 +21,7 @@
  * struct video_uc_platdata - uclass platform data for a video device
  *
  * This holds information that the uclass needs to know about each device. It
- * is accessed using dev_get_uclass_platdata(dev). See 'Theory of operation' at
+ * is accessed using dev_get_uclass_plat(dev). See 'Theory of operation' at
  * the top of video-uclass.c for details on how this information is set.
  *
  * @align: Frame-buffer alignment, indicating the memory boundary the frame
@@ -125,7 +125,7 @@
  *
  * Note: This function is for internal use.
  *
- * This uses the uclass platdata's @size and @align members to figure out
+ * This uses the uclass plat's @size and @align members to figure out
  * a size and position for each frame buffer as part of the pre-relocation
  * process of determining the post-relocation memory layout.
  *