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/hisilicon/poplar/poplar.c b/board/hisilicon/poplar/poplar.c
index 8c8015e..b8be4ce 100644
--- a/board/hisilicon/poplar/poplar.c
+++ b/board/hisilicon/poplar/poplar.c
@@ -40,7 +40,7 @@
 struct mm_region *mem_map = poplar_mem_map;
 
 #if !CONFIG_IS_ENABLED(OF_CONTROL)
-static const struct pl01x_serial_platdata serial_platdata = {
+static const struct pl01x_serial_plat serial_plat = {
 	.base = REG_BASE_UART0,
 	.type = TYPE_PL010,
 	.clock = 75000000,
@@ -48,7 +48,7 @@
 
 U_BOOT_DEVICE(poplar_serial) = {
 	.name = "serial_pl01x",
-	.plat = &serial_platdata,
+	.plat = &serial_plat,
 };
 #endif