Make the u-boot binary name configurable. Use the existing variable
UBOOT_BINARYNAME which is evaluated from the UBOOT_BINARY.
(From OE-Core rev: e588cde6aed1e699a055e3481df0f3dc719c9774)
Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>