Move vexpress-qemu configuration form meta-mender-qemu.
Move vexpress-qemu configuration form meta-mender-qemu.

Device specific config should be supported in one Yocto layer
together with different hardware.

bboozzoo/meta-mender,GregorioDiStefano/meta-mender,bboozzoo/meta-mender,GregorioDiStefano/meta-mender,bboozzoo/meta-mender,bboozzoo/meta-mender,GregorioDiStefano/meta-mender