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/isee/igep00x0/igep00x0.c b/board/isee/igep00x0/igep00x0.c
index e0ca3c2..6a7da50 100644
--- a/board/isee/igep00x0/igep00x0.c
+++ b/board/isee/igep00x0/igep00x0.c
@@ -29,7 +29,7 @@
 #include <fdt_support.h>
 #include "igep00x0.h"
 
-static const struct ns16550_platdata igep_serial = {
+static const struct ns16550_plat igep_serial = {
 	.base = OMAP34XX_UART3,
 	.reg_shift = 2,
 	.clock = V_NS16550_CLK,