Kill unneeded #include wherever possible

Tested on Linux, FreeBSD, NetBSD, OpenBSD, DOS.
Thanks to Jonathan A. Kollasch and Idwer Vollering for testing.

Corresponding to flashrom svn r1057.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Idwer Vollering <vidwer+lists.flashrom@gmail.com>
diff --git a/chipset_enable.c b/chipset_enable.c
index 02d139e..d124291 100644
--- a/chipset_enable.c
+++ b/chipset_enable.c
@@ -27,12 +27,10 @@
 
 #define _LARGEFILE64_SOURCE
 
-#include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
+#include <unistd.h>
 #include "flash.h"
 
 #if defined(__i386__) || defined(__x86_64__)