Sub: apply yaw input scaling in manual mode

Close bluerobotics/ardusub#68

ArduSub/control_manual.cpp

@@ -28,7 +28,7 @@ void Sub::manual_run()
 
     motors.set_roll(channel_roll->norm_input()*0.67f);
     motors.set_pitch(channel_pitch->norm_input()*0.67f);
-    motors.set_yaw(channel_yaw->norm_input()*0.67f);
+    motors.set_yaw(channel_yaw->norm_input() * 0.67f * g.acro_yaw_p / ACRO_YAW_P);
     motors.set_throttle(channel_throttle->norm_input());
     motors.set_forward(channel_forward->norm_input()*0.67f);
     motors.set_lateral(channel_lateral->norm_input()*0.67f);