drivers: add support for virtio

[icexin]

Although the goal of eggos is to run on bare metal, supporting virtio allows us to run eggos on cloud servers.

[aidansteele]

I just asked some people on Twitter and it looks like they confirmed that virtio won't be helpful for EC2. Newer instances use "Nitro" and older instances used Xen: https://twitter.com/_msw_/status/1427460582270070786

[prologic]

No but virtio is required/helpful to pretty much any other cloud provider, e.g: DigitalOcean, Vultr, and even on-prem stuff like Proxmox VE, etc.

AWS EC2 is just special 😉

[aidansteele]

Oh that's good to know! I only have experience with EC2 - it's good that the other clouds have mostly standardised. This makes a lot of sense then.