KVM: PPC: Book3S PR: Pass through MSR TM and TS bits to shadow_msr

PowerPC TM functionality needs MSR TM/TS bits support in hardware level.
Guest TM functionality can not be emulated with "fake" MSR (msr in magic
page) TS bits.

This patch syncs TM/TS bits in shadow_msr with the MSR value in magic
page, so that the MSR TS value which guest sees is consistent with actual
MSR bits running in guest.

Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>