Move FIFO and write size to CaptureConfig structure.

Now configured from baseband, where write size and appropriate FIFO size is known.

firmware/common/message_queue.hpp

@@ -70,6 +70,10 @@ public:
 		}
 	}
 
+	bool is_empty() const {
+		return fifo.is_empty();
+	}
+
 private:
 	FIFO<uint8_t> fifo;
 	Mutex mutex_write;
@@ -92,10 +96,6 @@ private:
 		return fifo.len();
 	}
 
-	bool is_empty() const {
-		return fifo.is_empty();
-	}
-
 	bool push(const void* const buf, const size_t len) {
 		chMtxLock(&mutex_write);
 		const auto result = fifo.in_r(buf, len);