Move Thread WORKING_AREAs out of classes.

Limited where and how you could instantiate the classes.

firmware/baseband/baseband_thread.cpp

@@ -42,8 +42,10 @@
 
 #include <array>
 
+WORKING_AREA(baseband_thread_wa, 2048);
+
 Thread* BasebandThread::start(const tprio_t priority) {
-	return chThdCreateStatic(wa, sizeof(wa),
+	return chThdCreateStatic(baseband_thread_wa, sizeof(baseband_thread_wa),
 		priority, ThreadBase::fn,
 		this
 	);