Merge tag 'efi-2020-07-rc3' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi

Pull request for UEFI sub-system for efi-2020-07-rc3

A series of patches introduces the possibility to manage UEFI variables
via an OP-TEE module. CONFIG_EFI_MM_COMM_TEE enables this. If this
option is not specified the U-Boot behavior remains unchanged. A defconfig
is provided for compile testing (lx2160ardb_tfa_stmm_defconfig).

An incorrect UEFI memory allocation for fsl-layerscape is fixed