hikey960-efi-prebuilt.sh: add option to use files from directory instead of downloading
hikey960-efi-prebuilt.sh: add option to use files from directory instead of downloading

Signed-off-by: Volker Eckert <91301165d210f5811bb99e8816e8216d7c92528b@arm.com>

96boards-hikey/tools-images-hikey960,96boards-hikey/tools-images-hikey960