builderthread.py: Keep 'SPL'

On i.MX platforms the SPL binary is called "SPL" so make sure we keep
that.

Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/builderthread.py b/tools/buildman/builderthread.py
index ce1cfdd..cf25bb8 100644
--- a/tools/buildman/builderthread.py
+++ b/tools/buildman/builderthread.py
@@ -356,7 +356,7 @@
         # Now write the actual build output
         if keep_outputs:
             self.CopyFiles(result.out_dir, build_dir, '', ['u-boot*', '*.bin',
-                '*.map', '*.img', 'MLO', 'include/autoconf.mk',
+                '*.map', '*.img', 'MLO', 'SPL', 'include/autoconf.mk',
                 'spl/u-boot-spl*'])
 
     def CopyFiles(self, out_dir, build_dir, dirname, patterns):