math/libdivide: fix build on armv6/armv7

The NEON code included in this library is for arm64 only.
Disable use of NEON on armv6/armv7.

See https://github.com/ridiculousfish/libdivide/issues/102.

PR: 265870
Reported by: fuz (at) fuz.su

(cherry picked from commit fbab55b27f97ce1d6cf067a1583b28716f2e127c)