[rotorcraft] fix hidden bug in ref_quat_float

thanks Antoine
	modified:   conf/modules/cam_roll.xml
	modified:   sw/airborne/modules/cam_control/cam_roll.c
	modified:   sw/airborne/subsystems/imu/imu_drotek_10dof_v2.c
	new file:   conf/radios/TURNIGY_PPM.xml