i40e: add VF capabilities to virtual channel interface

To prepare for the changes coming up in the X722 device and future
devices, the virtual channel interface has to change slightly. The VF
driver can now report what its capable of supporting, which then informs
the PF driver when it sends the configuration information back to the
VF.

A 1.1 VF driver on a 1.0 PF driver should not send its capabilities.
Likewise, a 1.1 PF driver controlling a 1.0 VF driver should not expect
or depend upon receiving the VF capabilities.

All other aspects of the API are unchanged.

Change-ID: I530cc55f107edd1ee8bdf95830aa90b87854058a
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Anjali Singhai <anjali.singhai@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>