env: Always use char for default_environment

Sometimes we use uchar and sometimes char for the default environment
array. By always using char, we can get rid of some explicit casts.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/Marvell/mvebu_armada-37xx/board.c b/board/Marvell/mvebu_armada-37xx/board.c
index 2de9c2a..d7b6eca 100644
--- a/board/Marvell/mvebu_armada-37xx/board.c
+++ b/board/Marvell/mvebu_armada-37xx/board.c
@@ -87,7 +87,7 @@
 #ifdef CONFIG_BOARD_LATE_INIT
 int board_late_init(void)
 {
-	char *ptr = (char *)&default_environment[0];
+	char *ptr = &default_environment[0];
 	struct udevice *dev;
 	struct mmc *mmc_dev;
 	bool ddr4, emmc;