lib/crypto: nh: Restore dependency of arch code on !KMSAN
Since the architecture-specific implementations of NH initialize memory
in assembly code, they aren't compatible with KMSAN as-is.
Fixes: 382de740759a ("lib/crypto: nh: Add NH library")
Link: https://lore.kernel.org/r/20260105053652.1708299-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>