change rsa_pss salt type

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/pk.c b/library/pk.c
index ee10980..091cb6b 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -546,7 +546,7 @@
     }
 
 #if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT) && defined(MBEDTLS_USE_PSA_CRYPTO)
-    return( mbedtls_pk_psa_sign_ext( PSA_ALG_RSA_PSS_ANY_SALT(
+    return( mbedtls_pk_psa_sign_ext( PSA_ALG_RSA_PSS(
                                         mbedtls_psa_translate_md( md_alg ) ),
                                      ctx->pk_ctx, hash, hash_len,
                                      sig, sig_size, sig_len ) );