Guard tinycrypt files with MBEDTLS_USE_UECC
diff --git a/include/tinycrypt/ecc.h b/include/tinycrypt/ecc.h
index 8abc949..ede7544 100644
--- a/include/tinycrypt/ecc.h
+++ b/include/tinycrypt/ecc.h
@@ -68,6 +68,7 @@
  *
  */
 
+#if defined(MBEDTLS_USE_UECC)
 #ifndef __TC_UECC_H__
 #define __TC_UECC_H__
 
@@ -543,3 +544,4 @@
 #endif
 
 #endif /* __TC_UECC_H__ */
+#endif /* MBEDTLS_USE_UECC */