The EFI test driver is being mainlined as an effort to help firmware developers. The EFI Test driver is used by the Firmware Test Suite (FTWS) for testing the UEFI runtime interface readiness of the firmware. This less than thousand lines of code driver exports the UEFI runtime service interfaces into user-space to then be analyzed by the FTWS.
This driver, exposed via EFI_TEST, up to now has been maintained out-of-tree. This driver is maintained by Canonical. Those wanting more information about the Firmware Test Suite can visit this Ubuntu Wiki page.
Other EFI changes this cycle include ARM support in the EFI ESRT driver and other smaller features and fixes. More details via Ingo Molnar's pull request.