iavf: negotiate PTP capabilities

iavf: negotiate PTP capabilities

Add a new extended capabilities negotiation to exchange information from
the PF about what PTP capabilities are supported by this VF. This
requires sending a VIRTCHNL_OP_1588_PTP_GET_CAPS message, and waiting
for the response from the PF. Handle this early on during the VF
initialization.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Co-developed-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Signed-off-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>