fix ci fail without RSA_C

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/pk.c b/library/pk.c
index 0a7a40b..5171961 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -544,11 +544,14 @@
         return( mbedtls_pk_sign( ctx, md_alg, hash, hash_len,
                                  sig, sig_size, sig_len, f_rng, p_rng ) );
     }
-
-    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 ) );
+#if defined(MBEDTLS_RSA_C)
+    return( mbedtls_pk_psa_rsa_sign_ext( PSA_ALG_RSA_PSS(
+                                            mbedtls_psa_translate_md( md_alg ) ),
+                                         ctx->pk_ctx, hash, hash_len,
+                                         sig, sig_size, sig_len ) );
+#else /* MBEDTLS_RSA_C */
+    return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+#endif /* !MBEDTLS_RSA_C */
 
 }
 #endif /* MBEDTLS_PSA_CRYPTO_C */
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 76b7a1b..cc4d6f2 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -197,10 +197,10 @@
 }
 
 #if defined(MBEDTLS_PSA_CRYPTO_C)
-int mbedtls_pk_psa_sign_ext( psa_algorithm_t psa_alg_md, void *pk_ctx,
-                             const unsigned char *hash, size_t hash_len,
-                             unsigned char *sig, size_t sig_size,
-                             size_t *sig_len )
+int  mbedtls_pk_psa_rsa_sign_ext( psa_algorithm_t psa_alg_md, void *pk_ctx,
+                                  const unsigned char *hash, size_t hash_len,
+                                  unsigned char *sig, size_t sig_size,
+                                  size_t *sig_len )
 {
     mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) pk_ctx;
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -269,10 +269,10 @@
         return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
 #endif /* SIZE_MAX > UINT_MAX */
 
-    return( mbedtls_pk_psa_sign_ext( PSA_ALG_RSA_PKCS1V15_SIGN(
-                                        mbedtls_psa_translate_md( md_alg ) ),
-                                     ctx, hash, hash_len,
-                                     sig, sig_size, sig_len ) );
+    return(  mbedtls_pk_psa_rsa_sign_ext( PSA_ALG_RSA_PKCS1V15_SIGN(
+                                            mbedtls_psa_translate_md( md_alg ) ),
+                                          ctx, hash, hash_len,
+                                          sig, sig_size, sig_len ) );
 }
 #else
 static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
diff --git a/library/pk_wrap.h b/library/pk_wrap.h
index e310005..5dae6b4 100644
--- a/library/pk_wrap.h
+++ b/library/pk_wrap.h
@@ -150,10 +150,12 @@
 int mbedtls_pk_error_from_psa_rsa( psa_status_t status );
 #endif
 
-int mbedtls_pk_psa_sign_ext( psa_algorithm_t psa_alg_md, void *ctx,
-                             const unsigned char *hash, size_t hash_len,
-                             unsigned char *sig, size_t sig_size,
-                             size_t *sig_len );
+#if defined(MBEDTLS_RSA_C)
+int  mbedtls_pk_psa_rsa_sign_ext( psa_algorithm_t psa_alg_md, void *ctx,
+                                  const unsigned char *hash, size_t hash_len,
+                                  unsigned char *sig, size_t sig_size,
+                                  size_t *sig_len );
+#endif /* MBEDTLS_RSA_C */
 
 #endif /* MBEDTLS_PSA_CRYPTO_C */