Fix build problems under FreeBSD

CHANGELOG

@@ -2,6 +2,8 @@
 Changes for U-Boot 1.0.0:
 ======================================================================
 
+* Fix build problems under FreeBSD
+
 * Add generic filesystem image type
 
 * Make fatload set filesize environment variable

tools/mkimage.c

@@ -422,7 +422,7 @@ NXTARG:		;
 	}
 
 	/* We're a bit of paranoid */
-#if defined(_POSIX_SYNCHRONIZED_IO) && !defined(__sun__)
+#if defined(_POSIX_SYNCHRONIZED_IO) && !defined(__sun__) && !defined(__FreeBSD__)
 	(void) fdatasync (ifd);
 #else
 	(void) fsync (ifd);
@@ -472,7 +472,7 @@ NXTARG:		;
 	(void) munmap((void *)ptr, sbuf.st_size);
 
 	/* We're a bit of paranoid */
-#if defined(_POSIX_SYNCHRONIZED_IO) && !defined(__sun__)
+#if defined(_POSIX_SYNCHRONIZED_IO) && !defined(__sun__) && !defined(__FreeBSD__)
 	(void) fdatasync (ifd);
 #else
 	(void) fsync (ifd);