Merge tag 'efi-2020-04-rc4-2' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi

Merge tag 'efi-2020-04-rc4-2' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi

Pull request for UEFI sub-system for efi-2020-04-rc4 (2)

In Linux next-20200228 patches have been merged to load an initial ramdisk
using an EFI_LOAD_FILE2_PROTOCOL provided by the firmware. See commit
ec93fc371f01 ("efi/libstub: Add support for loading the initrd from a
device path"). The idea behind it is that the firmware should be
responsible for validating the initrd in a secure boot setup.

This pull-request comprises a patch series which let's U-Boot provide an
initial implementation of the EFI_LOAD_FILE2_PROTOCOL providing the initrd.