[OE-core] qemu-config & non-gplv3

[Saul Wold]

Richard,

I was reminded again about the need to do non-GPLv3 sooner and more 
often.  I ran that today for core-image-basic on x86 and found 3 issues, 
first 2 were easy and will be in tonight's consolidated pull.

This issue again was with qemu-config dragging in GPLv3 licensed stuff 
and thus not having dependencies met. I understand the need for those 
packages in a development/debug environment, but we need a flexible way 
to enable and disable that task.

I know the easy way would be to club it over the head and remove 
qemu-config from qemu.inc's MACHINE_ESSENTIAL_EXTRA_RDEPENDS, but that's 
not the correct way!

We can make it be MACHINE_EXTRA_RDEPENDS or maybe more flexibly an 
IMAGE_FEATURE that can be disabled for minimal or non-GPLv3 builds.

Thoughts?

Thanks
-- 
     Sau!

Saul Wold
Yocto Component Wrangler @ Intel
Yocto Project / Poky Build System