emulators/qemu: Update version 6.2.0=>7.0.0

Users who want to stick with 6.X branch please check UPDATING or use
qemu6. As previous qemu comes with three flavors: the default with X11
support, -nox11 without X11 support and -tools which instals only a
subset of entire qemu.

Relnotes: https://wiki.qemu.org/ChangeLog/7.0