Taking both the FreeBSD[1] and Alpine[1] patch concepts;

provide non-GLIBC definations for HMT_*.

Provide FreeBSD ASM base for __ppc_get_timebase.
On alternately use __builtin_ppc_get_timebase which is described
on https://gcc.gnu.org/onlinedocs/gcc/Basic-PowerPC-Built-in-Functions-Available-on-all-Configurations.html
an not depended on glibc/musl.

[1] https://github.com/freebsd/freebsd-ports/blob/15d22e1c70da81aaa5751ad0d82f92e9451c4d81/databases/mariadb106-server/files/patch-include_my__cpu.h
[2] https://gitlab.alpinelinux.org/alpine/aports/-/blob/master/main/mariadb/ppc-remove-glibc-dep.patch