Revert "libc & libm: use hard float"

This reverts commit 0e7a911306cd60880ff93bc7506f5560c4ec511f.
Fix sysconf(3) for _SC_GETGR_R_SIZE_MAX and _SC_GETPW_R_SIZE_MAX.

Change-Id: Ie16cb21c1a5a2bdce8502b5974e2c4dbb1d679ce