updated for mbed-os 5.5

Fork of Task121 by Nicholas Outram

Revision:
11:d7337ffe7f85
Parent:
9:5ac40ff61514
--- a/mbed-os.lib	Thu Jul 16 08:39:50 2020 +0000
+++ b/mbed-os.lib	Thu Jul 16 09:47:03 2020 +0100
@@ -1,1 +1,1 @@
-https://github.com/ARMmbed/mbed-os/#165be79392ae7b1bee4388d2bc8ed8281978f07c
\ No newline at end of file
+https://github.com/ARMmbed/mbed-os/#a6207cadad0acd1876f436dc6baeddf46c42af06
\ No newline at end of file