PowerPC: Adjust multiarch Implies for PowerPC64

This patch adds Implies files on multiarch folder for POWER chips so
multirach is enabled when building with --with-cpu and powerN
option.
PowerPC: multiarch memcpy for PowerPC64
PowerPC: multirach memcmp for PowerPC64
PowerPC: multiarch memset/bzero for PowerPC64
PowerPC: multiarch mempcpy for PowerPC64
PowerPC: multiarch memchr for PowerPC64
PowerPC: multiarch memrchr for PowerPC64
PowerPC: multiarch rawmemchr for PowerPC64
PowerPC: multiarch strlen for PowerPC64
PowerPC: multiarch strnlen for PowerPC64
PowerPC: multiarch strcasecmp for PowerPC64
PowerPC: multiarch strncasecmp for PowerPC64
PowerPC: multiarch strncmp for PowerPC64
PowerPC: multiarch strchr for PowerPC64
PowerPC: multiarch strchrnul for PowerPC64
PowerPC: multiarch wcschr for PowerPC64
PowerPC: multiarch wcsrchr for PowerPC64
PowerPC: multiarch wcscpy for PowerPC64.
PowerPC: multiarch wordcopy for PowerPC64
PowerPC: multiarch strcpy for PowerPC64