The qemu TCG parts that it presumably links to are GPLv2, so the combined project is GPLv2 by necessity[1]. I think that's all they're trying to get across.
[1]: apart from viral licenses being pretty much meaningless under EU copyright law
[1]: apart from viral licenses being pretty much meaningless under EU copyright law
QEMU does something similar:
https://github.com/qemu/qemu/blob/master/LICENSEI think you could phrase that better. Maybe something like “This projects builds on GPLv2-licensed code, so the project is GPLv2-licensed. If you want to use our additions in isolation, you can choose to use them as either GPLv2 or MIT licensed”?