Add Cisco c9000v (cat9kv)

[hellt]

Here is a qemu string from eve running cat9kv

/opt/qemu-5.2.0/bin/qemu-system-x86_64 -nographic
-device e1000,netdev=net0,mac=50:00:00:08:00:00 -netdev tap,id=net0,ifname=vunl0_8_0,script=no 
-device e1000,netdev=net1,mac=50:00:00:08:00:01 -netdev tap,id=net1,ifname=vunl0_8_1,script=no 
-smp 4 -m 18432 -name C9K -uuid 99c918f2-3da5-4380-94dc-a821d979fd46
-drive file=virtioa.qcow2,if=virtio,bus=0,unit=0,cache=none
-machine type=pc,accel=kvm -vga std -usbdevice tablet -boot order=cd -cdrom config.iso

/cc @ipspace - in case you want to give it a try. Seems like lots of mem needs to be sacrificed, and this could've explained the boot stall during our initial try /cc @kaelemc - in case you want to make another contribution ;)

[kaelemc]

Created #225 to add support for this.

[hellt]

added in #225