Update mbed-os to its development branch

Patater · Patater · commit 678fe410820c · 2020-11-26T12:12:20.000Z
diff --git a/mbed-os.lib b/mbed-os.lib
@@ -1 +1 @@
-https://github.com/ARMmbed/mbed-os/#f2278567d09b9ae9f4843e1d9d393526b9462783
+https://github.com/ARMmbed/mbed-os/

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-https://github.com/ARMmbed/mbed-os/#f2278567d09b9ae9f4843e1d9d393526b9462783`
	`1`	`+https://github.com/ARMmbed/mbed-os/`