Restore does not rewind the guest TSC on WHP

After restore, the guest TSC should equal its value in the snapshot. On WHP hosts with TscAdjustSupport, it also includes the time since the snapshot. KVM (after #2015) and MSHV restore it exactly.

Writing TSC shifts TSC_ADJUST by the same amount, and writing TSC_ADJUST shifts TSC back, so restoring both undoes the rewind. Clearing TscAdjustSupport, as the MSHV driver does, fixes it.