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/drivers/core/regmap.c b/drivers/core/regmap.c
index c2bed88..4baacab 100644
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -60,8 +60,8 @@
 }
 
 #if CONFIG_IS_ENABLED(OF_PLATDATA)
-int regmap_init_mem_platdata(struct udevice *dev, fdt_val_t *reg, int count,
-			     struct regmap **mapp)
+int regmap_init_mem_plat(struct udevice *dev, fdt_val_t *reg, int count,
+			 struct regmap **mapp)
 {
 	struct regmap_range *range;
 	struct regmap *map;