This reverts commit 39d68495.

 - add driver prefix to perf counter naming

There seem to be more issues in combination with MAVLink.

fixes hardfaults, e.g. when device not connected

The vtol module will read them later on.

decimal for the uuv_att_control gain parameters was not defined. So
QGroundControl displays them as integers what is rather unhandy.

Specify orientaiton of ADIS16448 IMU for from the rc.sensors

WIP: Currently only handling one orientation

 - minor improvement that helps to determine the sensor publication rate
as soon as possible

 - requires https://github.com/PX4/PX4-ECL/pull/1020

 - IMU integrator set max dt based on final return size (uint16)
 - improve integration consuming gyro as needed then integrate all available accel until caught up
 - increase required number of samples for sensor rate measurement (online Welford mean)

 - this can catch subtle failures that occur after self hours of continuous operation on some units