igb: Fix DMA requester specification for Tx packet

igb: Fix DMA requester specification for Tx packet

igb used to specify the PF as DMA requester when reading Tx packets.
This made Tx requests from VFs to be performed on the address space of
the PF, defeating the purpose of SR-IOV. Add some logic to change the
requester depending on the queue, which can be assigned to a VF.

Fixes: 3a977deebe ("Intrdocue igb device emulation")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>