virtchnl: add support for enabling PTP on iAVF

virtchnl: add support for enabling PTP on iAVF

Add support for allowing a VF to enable PTP feature - Rx timestamps

The new capability is gated by VIRTCHNL_VF_CAP_PTP, which must be
set by the VF to request access to the new operations. In addition, the
VIRTCHNL_OP_1588_PTP_CAPS command is used to determine the specific
capabilities available to the VF.

This support includes the following additional capabilities:

* Rx timestamps enabled in the Rx queues (when using flexible advanced
  descriptors)
* Read access to PHC time over virtchnl using
  VIRTCHNL_OP_1588_PTP_GET_TIME

Extra space is reserved in most structures to allow for future
extension (like set clock, Tx timestamps).  Additional opcode numbers
are reserved and space in the virtchnl_ptp_caps structure is
specifically set aside for this.
Additionally, each structure has some space reserved for future
extensions to allow some flexibility.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>