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/board/timll/devkit8000/devkit8000.c b/board/timll/devkit8000/devkit8000.c
index 2420c28..8753836 100644
--- a/board/timll/devkit8000/devkit8000.c
+++ b/board/timll/devkit8000/devkit8000.c
@@ -47,7 +47,7 @@
 	0
 };
 
-static const struct ns16550_platdata devkit8000_serial = {
+static const struct ns16550_plat devkit8000_serial = {
 	.base = OMAP34XX_UART3,
 	.reg_shift = 2,
 	.clock = V_NS16550_CLK,