Guard tinycrypt files with MBEDTLS_USE_UECC
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index 9a4c0a5..d3e72a5 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -53,6 +53,7 @@
  *  POSSIBILITY OF SUCH DAMAGE.
  */
 
+#if defined(MBEDTLS_USE_UECC)
 #include <tinycrypt/ecc.h>
 #include <tinycrypt/ecc_dsa.h>
 
@@ -292,3 +293,4 @@
 	return (int)(uECC_vli_equal(rx, r, num_words) == 0);
 }
 
+#endif /* MBEDTLS_USE_UECC */