PTP devices not available about lis-next

[chvalean]

@adanielov please check if Time sync Integration service is enabled for your VM.

PS > Get-VMIntegrationService rhel_7.5

VMName   Name                    Enabled PrimaryStatusDescription SecondaryStatusDescription
------   ----                    ------- ------------------------ --------------------------
rhel_7.5 Time Synchronization    True    OK

Try to toggle this On/Off from the VM settings or via PS, inside the VM this will be presented by an event in dmesg similar to this:
hv_utils: TimeSync IC version 3.0

If you're missing that line in dmesg, then most likely the TimeSync Integration Service is not enabled for the VM.