dm: treewide: Rename dev_get_platdata() to dev_get_plat()

Rename this to be consistent with the change from 'platdata'.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dwmmc.h b/include/dwmmc.h
index 4515a44..51ab74e 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -259,7 +259,7 @@
  *	.plat_auto	= sizeof(struct rockchip_mmc_plat),
  *
  * To access platform data:
- *	struct rockchip_mmc_plat *plat = dev_get_platdata(dev);
+ *	struct rockchip_mmc_plat *plat = dev_get_plat(dev);
  *
  * See rockchip_dw_mmc.c for an example.
  *