i40e: Move RSS table size for VSIs to the VSI struct

Since all VSIs don't have the same RSS table size,
have one for each VSI instead of having a single define
for RSS table size

Change-ID: Ic2c7c66e4a389d4b6c8841a707510a9735041f02
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>