Fix indentation in make_def_config.py

Function concatenate_files() used mix of tabs and spaces,
and python3 was very unhappy about this.

Signed-off-by: Volodymyr Babchuk <vlad.babchuk@gmail.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

br-ext/scripts/make_def_config.py

@@ -24,11 +24,11 @@ def get_args():
     return parser.parse_args()
 
 def concatenate_files(top_dir, dst, srcs):
-	with open(dst, 'w') as outfile:
-	    for fname in srcs:
-		with open(fname) as infile:
-		    for line in infile:
-			outfile.write(line.replace('%TOP_DIR%', top_dir))
+    with open(dst, 'w') as outfile:
+        for fname in srcs:
+            with open(fname) as infile:
+                for line in infile:
+                    outfile.write(line.replace('%TOP_DIR%', top_dir))
 
 def main():
     args = get_args()