change to mbed-os w/ precompiled header

oclyke · oclyke · commit ac56eaeeabd2 · 2020-11-23T09:50:55.000-07:00
diff --git a/cores/mbed-os b/cores/mbed-os
@@ -1 +1 @@
-Subproject commit 14231bca36940a24f1222c30da46e4d0c32594d5
+Subproject commit ef42d9b7e6effab9b0e2f8e551e0aa4fd6aae188
