certs: unify blacklist_hashes.c and blacklist_nohashes.c

These two files are very similar. Unify them.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>