This directory was created when U-Boot gained the ability to run as an
EFI app in 2015. Since then the EFI-loader feature has been added.
The code in lib/efi is not actually used by the loader, so the name is
confusing.
Rename the directory to efi_client to indicate that it includes files
just for U-Boot being a client of EFI, i.e. the EFI app and stub.
Signed-off-by: Simon Glass <sjg@chromium.org>
