[caffe2/utils] Add explicit rule to avoid package boundary violation
Summary:
Add a rule to wrap proto_utils.h and depend on that, rather than
relying on a glob which violates package boundaries.
Reviewed By: igorsugak
Differential Revision: D29273453
fbshipit-source-id: 08f198a03d06ee2fdf61f5dbe1d0087db22aec8b
