Merge tag 'efi-2020-10-rc2' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi

Pull request for UEFI sub-system for efi-2020-10-rc2

This series comprises error corrections for the UEFI subsystem:

* make the memory size reserved for the U-Boot stack customizable
  and reduce it for the MAIX board
* correct build dependencies for UEFI unit test
* enable read-only UEFI variable are enabled with the TEE backend
* add 10 ms wait to sysreset to fix a problem with unit testing