i40e: re-enable PTP L4 capabilities for XL710 if FW >6.0

Starting with XL710 FW 5.3 PTP L4 was disabled for XL710 due to a bug.  The
bug has since been resolved in XL710 FW >6.0 and PTP L4 can now be
re-enabled on those devices with updated firmware.
Signed-off-by: NAlan Brady <alan.brady@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -9074,6 +9074,11 @@ static int i40e_sw_init(struct i40e_pf *pf)
 	    (pf->hw.aq.fw_maj_ver >= 5)))
 		pf->hw_features |= I40E_HW_USE_SET_LLDP_MIB;
 
+	/* Enable PTP L4 if FW > v6.0 */
+	if (pf->hw.mac.type == I40E_MAC_XL710 &&
+	    pf->hw.aq.fw_maj_ver >= 6)
+		pf->hw_features |= I40E_HW_PTP_L4_CAPABLE;
+
 	if (pf->hw.func_caps.vmdq) {
 		pf->num_vmdq_vsis = I40E_DEFAULT_NUM_VMDQ_VSI;
 		pf->flags |= I40E_FLAG_VMDQ_ENABLED;