qed: Add CONFIG_QED_SRIOV

Add support for a new Kconfig option for qed* driver which would allow
[eventually] the support in VFs.

This patch adds the necessary logic in the PF to learn about the possible
VFs it will have to support [Based on PCI configuration space and HW],
and prepare a database with an entry per-VF as infrastructure for future
interaction with said VFs.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>