The UBOOT_MACHINE variable needs to be set so the firmware utils can
know about some configuration settings which are board dependent. This
patch ensures the package is skipped in case UBOOT_MACHINE is unset
thus avoid its build in 'bitbake world' builds for incompatible
machines.
Fixes [YOCTO: #5223]
(From OE-Core rev: d9abcc0a2a691ca60cc1cb2f48f1748b0de73ac8)
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>