Revert "virtio_pci: use shared interrupts for virtqueues"

Revert "virtio_pci: use shared interrupts for virtqueues"

This reverts commit 07ec51480b5eb1233f8c1b0f5d7a7c8d1247c507.

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>