vDPA/ifcvf: decouple config/dev IRQ requester and vectors allocator from the adapter

This commit decouples the config irq requester, the device
shared irq requester and the MSI vectors allocator from
the adapter. So they can be safely invoked since probe
before the adapter is allocated.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Cc: stable@vger.kernel.org
Message-Id: <20221125145724.1129962-8-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>