As of version 3.7, Nettle added PowerPC64 assembly for several
algorithms. Unfortunately, they cause build to fail due to ABI mismatch:
gcm-hash.o: ABI version 1 is not compatible with ABI version 2 output
Disable assembler when ppc64 and musl are used for now.
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: Rui Salvaterra <rsalvaterra@gmail.com>