Reflect latest changes on UEFI ohai plugin

**This depends on https://github.com/crowbar/barclamp-deployer/pull/216**
I simply forgot to update the ohai plugin after extending it on the UEFI machine: https://github.com/crowbar/barclamp-deployer/pull/216/files#diff-46ef3dc0b387b487e8149f8c7ae501b1R47