psa_util/pk_wrap: remove redundant guards and optimize

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/pk_wrap.h b/library/pk_wrap.h
index 70d3d60..0664600 100644
--- a/library/pk_wrap.h
+++ b/library/pk_wrap.h
@@ -124,15 +124,14 @@
 #if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
 extern const mbedtls_pk_info_t mbedtls_ecdsa_opaque_info;
 extern const mbedtls_pk_info_t mbedtls_rsa_opaque_info;
+#endif /* MBEDTLS_PSA_CRYPTO_CLIENT */
 
-#if defined(MBEDTLS_RSA_C)
+#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_RSA_C)
 int mbedtls_pk_psa_rsa_sign_ext(psa_algorithm_t psa_alg_md,
                                 mbedtls_rsa_context *rsa_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_CLIENT */
+#endif /* MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_RSA_C */
 
 #endif /* MBEDTLS_PK_WRAP_H */
diff --git a/library/psa_util.c b/library/psa_util.c
index 3f81ed1..d0ac2cd 100644
--- a/library/psa_util.c
+++ b/library/psa_util.c
@@ -107,8 +107,7 @@
 };
 #endif
 
-#if defined(MBEDTLS_PSA_CRYPTO_CLIENT) && \
-    defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY)
+#if defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY)
 const mbedtls_error_pair_t psa_to_pk_ecdsa_errors[] =
 {
     { PSA_SUCCESS,                     0 },
diff --git a/library/psa_util_internal.h b/library/psa_util_internal.h
index 6a936fc..faa42fa 100644
--- a/library/psa_util_internal.h
+++ b/library/psa_util_internal.h
@@ -69,8 +69,7 @@
 extern const mbedtls_error_pair_t psa_to_pk_rsa_errors[8];
 #endif
 
-#if defined(MBEDTLS_PSA_CRYPTO_CLIENT) && \
-    defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY)
+#if defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY)
 extern const mbedtls_error_pair_t psa_to_pk_ecdsa_errors[7];
 #endif