Revert "virtio_pci: use shared interrupts for virtqueues"

Revert "virtio_pci: use shared interrupts for virtqueues"

This reverts commit 9a8a1fd5456736b1c222bf691367fefadd1329ce.

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>