Added function efx_ef10_get_vf_index to store the vf_index
in nic_data during probe

vf_index is needed in future patches to access a particular
VF in the VF data structure.

Moved efx_ef10_probe_pf and efx_ef10_probe_vf in order to
used efx_ef10_remove
Signed-off-by: NShradha Shah <sshah@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>