xrt: Make it possible for the device set active status on inputs

src/xrt/auxiliary/util/u_device.c

@@ -251,6 +251,11 @@ u_device_allocate(enum u_device_alloc_flags flags,
 	if (num_inputs > 0) {
 		xdev->num_inputs = num_inputs;
 		xdev->inputs = (struct xrt_input *)(ptr + offset_inputs);
+
+		// Set inputs to active initially, easier for drivers.
+		for (size_t i = 0; i < num_inputs; i++) {
+			xdev->inputs[i].active = true;
+		}
 	}
 
 	if (num_outputs > 0) {

src/xrt/include/xrt/xrt_device.h

@@ -180,6 +180,9 @@ struct xrt_hmd_parts
  */
 struct xrt_input
 {
+	//! Is this input active.
+	bool active;
+
 	int64_t timestamp;
 
 	enum xrt_input_name name;