Revert "hrtimer: Prevent enqueue of hrtimer on dead CPU"

This reverts commit 00c230771af726189a4b834e3f96cdc3005d33b3

Change-Id: Ida59ae660be7cc475f1e6559e375db64ea86b5a1
Merge "Revert "hrtimer: Prevent enqueue of hrtimer on dead CPU"" into jb4.2