Use variables from image-uefi.conf instead of hardcoding them in the
recipe.
(From OE-Core rev: e6bb6d31c4285a62b3e9e324c36b2baf439e7bae)
Signed-off-by: Dmitry Eremin-Solenikov <dmitry_eremin-solenikov@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>