devtool: open kconfig fragment in binary mode

When devtool writes to the kconfig fragment, it writes the output of
the diff command returned from pipe.communicate(). This function
returns binary objects. We should open the kconfig fragment file in
binary mode if we expect to write binary objects to it.

[YOCTO #11171]

(From OE-Core rev: 72bec63ab0e78753fb6ed1794d11beef9485c014)

Signed-off-by: Stephano Cetola <stephano.cetola@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/devtool/standard.py

@@ -1223,7 +1223,7 @@ def _create_kconfig_diff(srctree, rd, outfile):
         stdout, stderr = pipe.communicate()
         if pipe.returncode == 1:
             logger.info("Updating config fragment %s" % outfile)
-            with open(outfile, 'w') as fobj:
+            with open(outfile, 'wb') as fobj:
                 fobj.write(stdout)
         elif pipe.returncode == 0:
             logger.info("Would remove config fragment %s" % outfile)