Merge tag 'efi-2022-10-rc6' of https://source.denx.de/u-boot/custodians/u-boot-efi

Pull request for efi-2022-10-rc6

Documentation:

* doc: improve description of autostart

UEFI:

* prefix test functions with efi_st_ in the LoadImage unit test
* avoid a warning message in efi_initrd_deregister()