Upstreamed: Two bug fixes in idle/wakeup code

[paulusmack]

This records the fact that the two commits below in the hostos-1.0 release were submitted upstream and accepted after v4.8 was released. They are:

490b36e ("powerpc/64: Re-fix race condition between going idle and entering guest", 2016-10-21)
945f419 ("powerpc/64: Fix race condition in setting lock bit in idle/wakeup code", 2016-10-21)

These commits fix a sporadic soft-lockup in ktime_get_ts64() which has been observed on several systems.

These patches are in v4.9-rc3 with commit IDs 56c4622 and 09b7e37 and are marked for the stable trees.