string: only include inline-asm if UCLIBC_HAS_STRING_ARCH_OPT
string: only include inline-asm if UCLIBC_HAS_STRING_ARCH_OPT

Signed-off-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@gentoo.org>

joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc