Revert "virtio_pci: use shared interrupts for virtqueues"

Revert "virtio_pci: use shared interrupts for virtqueues"

This reverts commit 47e8b5efa134642408c901a6cd66c1c6bd64efe2.

Conflicts:
	drivers/virtio/virtio_pci_common.c

Unfortunately the idea does not work with threadirqs
as more than 32 queues can then map to a single interrupts.

Further, the cleanup seems to be one of the changes that broke
hybernation for some users. We are still not sure why
but revert helps.

This reverts the cleanup changes but keeps the affinity support.

Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>