virtchnl: add virtchnl version 2 ops

Virtchnl version 1 is an interface used by the current generation of
foundational NICs to negotiate the capabilities and configure the
HW resources such as queues, vectors, RSS LUT, etc between the PF
and VF drivers. It is not extensible to enable new features supported
in the next generation of NICs/IPUs and to negotiate descriptor types,
packet types and register offsets.

To overcome the limitations of the existing interface, introduce
the virtchnl version 2 and add the necessary opcodes, structures,
definitions, and descriptor formats. The driver also learns the
data queue and other register offsets to use instead of hardcoding
them. The advantage of this approach is that it gives the flexibility
to modify the register offsets if needed, restrict the use of
certain descriptor types and negotiate the supported packet types.

Co-developed-by: Alan Brady <alan.brady@intel.com>
Signed-off-by: Alan Brady <alan.brady@intel.com>
Co-developed-by: Joshua Hay <joshua.a.hay@intel.com>
Signed-off-by: Joshua Hay <joshua.a.hay@intel.com>
Co-developed-by: Madhu Chittim <madhu.chittim@intel.com>
Signed-off-by: Madhu Chittim <madhu.chittim@intel.com>
Co-developed-by: Phani Burra <phani.r.burra@intel.com>
Signed-off-by: Phani Burra <phani.r.burra@intel.com>
Co-developed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>