Do not require BRANCH= in coreboot and u-boot path descriptions

The firmware development paradigm changed such that firmware branches
are cut later in the cycle and very little ToT patches need to be
cherry-picked into branches. Let's not require the BRANCH= field in
u-boot/coreboot patch descriptions.

BUG=None
TEST='repo upload' of coreboot patches does not fail any more even if
     BRANCH= is not present in the patch description.

Change-Id: I64d2a7ced488166c271602395e7324d85676a8b8
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/196257
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
diff --git a/pre-upload.py b/pre-upload.py
index 9e2b896..650ec3f 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -858,14 +858,12 @@
                                _check_change_has_branch_field],
     "chromiumos/platform/mosys": [_check_change_has_branch_field],
     "chromiumos/platform/vboot_reference": [_check_change_has_branch_field],
-    "chromiumos/third_party/coreboot": [_check_change_has_branch_field,
-                                        _check_change_has_signoff_field],
+    "chromiumos/third_party/coreboot": [_check_change_has_signoff_field],
     "chromiumos/third_party/flashrom": [_check_change_has_branch_field],
     "chromiumos/third_party/kernel": [_run_checkpatch, _kernel_configcheck],
     "chromiumos/third_party/kernel-next": [_run_checkpatch,
                                            _kernel_configcheck],
-    "chromiumos/third_party/u-boot": [_run_checkpatch_no_tree,
-                                      _check_change_has_branch_field],
+    "chromiumos/third_party/u-boot": [_run_checkpatch_no_tree],
 }