Improve chrony clock settings

Co-Authored-By: Sebastian Heid <8442432+s4heid@users.noreply.github.com>

Author: MSSedusch

stemcell_builder/stages/bosh_azure_chrony/apply.sh

@@ -9,5 +9,5 @@ source $base_dir/lib/prelude_bosh.bash
 cat > $chroot/etc/chrony/conf.d/azure_ptp.conf <<EOF
 # created by $0
 # https://docs.microsoft.com/en-us/azure/virtual-machines/linux/time-sync#chrony
-refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0
+refclock PHC /dev/ptp_hyperv poll 3 dpoll -2 offset 0 stratum 2
 EOF