Add cortex-m-debug for itm print

Cargo.toml

@@ -12,6 +12,9 @@ version = "0.1.0"
 [dependencies]
 static-ref = "0.2.0"
 
+[dependencies.cortex-m-debug]
+git = "https://gitlab.henriktjader.com/pln/cortex-m-debug.git"
+
 [dependencies.cast]
 default-features = false
 version = "0.2.2"