Revert "Summary: Use hypervisor as clock source for system vms"

removing due to CLOUDSTACK-2872, ubuntu 12.04's libvirt isn't new enough

This reverts commit c7ebcb4e8c287ae88d2f6e6d71cc536612a5e635.
Squeak.

Signed-off-by: Prasanna Santhanam <tsp@apache.org>
cloudstack-804
CLOUDSTACK-4041 [ZWPSFailed to migrate a ROOT volume created on zone wide primary storage

While finding endpoint to send the migrate volume command, in case of zone wide storage pool, storage engine is picking a host among all connected hosts randomly. Hence a host may be from different cluster t

Signed-off-by: Sateesh Chodapuneedi <sateesh@apache.org>
CLOUDSTACK-4125: [Upgrade] after upgrade 3.0.7 GA -> 4.2 deploy guest VM
fail.