esp8266: Add support for frozen modules
diff --git a/esp8266/mpconfigport.h b/esp8266/mpconfigport.h
index cae5398..6d70c48 100644
--- a/esp8266/mpconfigport.h
+++ b/esp8266/mpconfigport.h
@@ -36,6 +36,7 @@
 #define MICROPY_LONGINT_IMPL        (MICROPY_LONGINT_IMPL_LONGLONG)
 #define MICROPY_FLOAT_IMPL          (MICROPY_FLOAT_IMPL_NONE)
 #define MICROPY_ERROR_REPORTING     (MICROPY_ERROR_REPORTING_TERSE)
+#define MICROPY_MODULE_FROZEN       (1)
 
 // type definitions for the specific machine