i386/sysdep.h: Remove STABS_* macros

uclibc is compiled with elf/dwarf and secondly HAVE_CPP_ASM_DEBUGINFO
is not defined so we generate bogus .stab sections needlessly

Some of post processing tools get confused when they see both
dwarf and stab sections

Signed-off-by: Khem Raj <raj.khem@gmail.com>