Merge tag 'efi-2019-04-rc2' of https://github.com/xypron2/u-boot

The patches fix multiple errors. Mentionable are:
- EFI unit tests (bootefi selftest) can run on i386.
- `make tests` executes the Unicode unit tests.

The LoadImage patch is preparing for further rework to be delivered
in v2019.07.