cros_bundle_firmware: Add defaults for exynos BL1, BL2 files

To reduce the number of mandatory parameters, use suitable defaults
for these filenames.

BUG=chromium-os:19724
TEST=manual: run cros_bundle_firmware without --bl1 and --bl2 parameters.
See that it still completes.

Change-Id: Ia17bcdf40464c262a559ef3c47fbf48f7b20a999
Reviewed-on: https://gerrit.chromium.org/gerrit/18326
Commit-Ready: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/host/lib/bundle_firmware.py b/host/lib/bundle_firmware.py
index 7fbd0bf..cf900b6 100644
--- a/host/lib/bundle_firmware.py
+++ b/host/lib/bundle_firmware.py
@@ -153,6 +153,10 @@
       self.bct_fname = os.path.join(build_root, 'bct', 'board.bct')
     if not self.bmpblk_fname:
       self.bmpblk_fname = os.path.join(build_root, 'default.bmpblk')
+    if not self.exynos_bl1:
+      self.exynos_bl1 = os.path.join(build_root, 'E5250.nbl1.bin')
+    if not self.exynos_bl2:
+      self.exynos_bl2 = os.path.join(build_root, 'smdk5250-spl.bin')
 
   def GetFiles(self):
     """Get a list of files that we know about.