enic: Add support for fw init command on sriov vf's

This patch fixes enic_probe to do a fw init devcmd for sriov vfs.
This enables vf driver in the guest to get into adapter init state without
having to explicitly issue an init fw cmd with portprofile info. But a
successful init on the vf will require the port profile information to be
pre-provisioned by the hypervisor via the pf

Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: Sujith Sankar <ssujith@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>