virtchnl2: add flow steering support

Add opcodes and corresponding message structure to add and delete
flow steering rules. Flow steering enables configuration
of rules to take an action or subset of actions based on a match
criteria. Actions could be redirect to queue, redirect to queue
group, drop packet or mark.

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Co-developed-by: Dinesh Kumar <dinesh.kumar@intel.com>
Signed-off-by: Dinesh Kumar <dinesh.kumar@intel.com>
Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>