Merge tag 'efi-2019-07-rc3' of git://git.denx.de/u-boot-efi

Pull request for UEFI sub-system for v2019.07-rc3

The development target for the UEFI sub-system is EBBR compliance. We have
already implemented some further protocols to enable running the UEFI Shell
and the UEFI SCT test suite.

As some boards are severely memory constrained make some of these extras
customizable.

Provide bug fixes. The most prominent ones let us pass the UEFI SCT memory
allocation tests.