mxsboot: remove unused include

Commit 276d3ebb883024d753cd9c69ab2fd243ffa1262e removed htole32() but missed
to remove the corresponding header. This is annoying, since BSD systems do not
have endian.h.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Michael Heimpold <mhei@heimpold.de>

tools/mxsboot.c

@@ -7,7 +7,6 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
-#include <endian.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>