Fix the fboss-oss build
Fix the fboss-oss build

Summary: Add missing generated file so that fboss_agent links correctly.

Reviewed By: yfeldblum

Differential Revision: D4354615

fbshipit-source-id: 642b2bd38dc028e1f20d5745fe6614e6ba21fa6c

peterlei/fboss,peterlei/fboss,peterlei/fboss,peterlei/fboss