Bionic/libm: enable optimized math functions on more QCOM targets.

allow more QCOM targets to use optimized math functions.

Change-Id: I76ee1bf951ae1c8397fef3af6e9937ed8cad9b62
libm: Fix multiple inclusion warning

Change-Id: Ifa732ec52fb582c34512cd1d09d918199ae7395e