virtio: support modern devices

fixes #17239 #17238

Change-Id: Ia5b6347110a60fab18852079b30dca6301010474
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6995
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

Add more missing headers following previous commits.

These also are only a problem on riscv64; I guess thread.h
must not be included in some arch header there.

virtio: Rework queue_dequeue to return a boolean.

It previously returned the cookie directly, which made it impossible
to distinguish between a NULL cookie and the function not having
anything to dequeue. This lead to some code setting a cookie that was
not actually used.

Return the dequeue status as a boolean and provide the cookie with an
optionally handed in pointer instead and adjust all users.

Change-Id: Iaac1726ac4bc7ae42bb96b8f0915852b6def5822
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1814
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

virtio: add driver for the virtio balloon device

* how-to for qemu: command line option: -balloon virtio
* in the monitor view
- to switch the vm size to 500MB: balloon 500
- to display balloon info: info balloon