esp8266: Enable micropython.schedule() with locking in pin callback.
diff --git a/esp8266/esp8266_common.ld b/esp8266/esp8266_common.ld
index f721c28..1da8356 100644
--- a/esp8266/esp8266_common.ld
+++ b/esp8266/esp8266_common.ld
@@ -100,6 +100,7 @@
         *py/qstr.o*(.literal* .text*)
         *py/repl.o*(.literal* .text*)
         *py/runtime.o*(.literal* .text*)
+        *py/scheduler.o*(.literal* .text*)
         *py/scope.o*(.literal* .text*)
         *py/sequence.o*(.literal* .text*)
         *py/showbc.o*(.literal* .text*)