kvm/x86: Update SynIC timers on guest entry only

kvm/x86: Update SynIC timers on guest entry only

Consolidate updating the Hyper-V SynIC timers in a
single place: on guest entry in processing KVM_REQ_HV_STIMER
request.  This simplifies the overall logic, and makes sure
the most current state of msrs and guest clock is used for
arming the timers (to achieve that, KVM_REQ_HV_STIMER
has to be processed after KVM_REQ_CLOCK_UPDATE).

Signed-off-by: Andrey Smetanin <[email protected]>
Reviewed-by: Roman Kagan <[email protected]>
CC: Gleb Natapov <[email protected]>
CC: Paolo Bonzini <[email protected]>
CC: Roman Kagan <[email protected]>
CC: Denis V. Lunev <[email protected]>
CC: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>