lib/math files not follow coding standard; float, double, and long double...

lib/math files not follow coding standard; float, double, and long double versions in separate files to reduce size of dumb link

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5270 42af7a65-404d-4744-a932-0658087f49c3