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/include/dm/platform_data/serial_sh.h b/include/dm/platform_data/serial_sh.h
index 711435d..69cd012 100644
--- a/include/dm/platform_data/serial_sh.h
+++ b/include/dm/platform_data/serial_sh.h
@@ -27,7 +27,7 @@
  * @clk_mode:	Clock mode, set internal (INT) or external (EXT)
  * @type:	Type of SCIF
  */
-struct sh_serial_platdata {
+struct sh_serial_plat {
 	unsigned long base;
 	unsigned int clk;
 	enum sh_clk_mode clk_mode;