pk_wrap: keep ECDSA_C for ECP_RESTARTABLE contexts

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/pk_wrap.h b/library/pk_wrap.h
index abfac7a..ac5c72f 100644
--- a/library/pk_wrap.h
+++ b/library/pk_wrap.h
@@ -60,7 +60,7 @@
                      int (*f_rng)(void *, unsigned char *, size_t),
                      void *p_rng);
 
-#if defined(MBEDTLS_PK_CAN_ECDSA_SOME) && defined(MBEDTLS_ECP_RESTARTABLE)
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
     /** Verify signature (restartable) */
     int (*verify_rs_func)(void *ctx, mbedtls_md_type_t md_alg,
                           const unsigned char *hash, size_t hash_len,