crypto: speck - add test vectors for Speck128-XTS

Add test vectors for Speck128-XTS, generated in userspace using C code.
The inputs were borrowed from the AES-XTS test vectors.

Both xts(speck128-generic) and xts-speck128-neon pass these tests.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

crypto/testmgr.c

@@ -3575,6 +3575,15 @@ static const struct alg_test_desc alg_test_descs[] = {
 				.dec = __VECS(serpent_xts_dec_tv_template)
 			}
 		}
+	}, {
+		.alg = "xts(speck128)",
+		.test = alg_test_skcipher,
+		.suite = {
+			.cipher = {
+				.enc = __VECS(speck128_xts_enc_tv_template),
+				.dec = __VECS(speck128_xts_dec_tv_template)
+			}
+		}
 	}, {
 		.alg = "xts(twofish)",
 		.test = alg_test_skcipher,