libm: These optimizations are only for Krait

 * Issues on other chipsets. Resync with CAF and only use on specific
   chipsets (Krait, Sparrow).

Change-Id: I6a11f3f8e3250359259edf5f57e0d9e7068c5375
Merge "libm: These optimizations are only for Krait" into jb-mr1