util/cbfstool: Remove redundant endian.h include

flashmap/fmap.c includes commonlib/bsd/sysincludes.h, which already
includes the necessary header for endian(3) functions (endian.h on
Linux and sys/endian.h on FreeBSD). This also resolves a compilation
error on macOS (tested on 10.5.7), as macOS does not provide endian.h.

Change-Id: I0cb17eacd253605b75db8cf734e71ca3fe24ad6c
Signed-off-by: Alex James <theracermaster@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60228
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

util/cbfstool/flashmap/fmap.c

@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: BSD-3-Clause or GPL-2.0-only */
 
 #include <ctype.h>
-#include <endian.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>