v2: properly save kvm system time msr registers

v2: properly save kvm system time msr registers

Currently, the msrs involved in setting up pvclock are not saved over
migration and/or save/restore. This patch puts their value in special
fields in our CPUState, and deal with them using vmstate.

kvm also has to account for it, by including them in the msr list
for the ioctls.

This is a backport from qemu-kvm.git

[v2: sucessfully build without kerneldir ]

Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit 1a03675db146dfc760b3b48b3448075189f142cc)