vxge: Enable SRIOV support in the driver.

- Enabled SRIOV support in the driver.
- Call __vxge_hw_verify_pci_e_info() for the PF only. This function
  verifies the negotiated link width and current link speed in the
  Link Status Register (offset 12h) which are reserved fields for VFs
  as per the SRIOV specification, section 3.5.8.
- Implemented David Miller's comment to remove the #ifdef CONFIG_PCI_IOV as
  these intefaces have NOP versions declared when the defintion is not set.

Signed-off-by: Sivakumar Subramani <sivakumar.subramani@neterion.com>
Signed-off-by: Rastapur Santosh <santosh.rastapur@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: David S. Miller <davem@davemloft.net>