bnx2x: Infrastructure for VF <-> PF request on PF side

Support interrupt from device which indicates VF has placed
A request on the VF <-> PF channel.
The PF driver issues a DMAE to retrieve the request from the VM
memory (the Ghost Physical Address of the request is contained
in the interrupt. The PF driver uses the GPA in the DMAE request,
which is translated by the IOMMU to the correct physical address).
The request which arrives is examined to recognize the sending VF.
The PF driver allocates a workitem to handle the VF Operation (vfop).

Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>