UAVORelay: add to TaskInfo and enable in Sparky
UAVORelay: fix compilation errors.

It also initializes CameraDesired since that is all it is currently
relaying.
UAVORelay: fix bug with wrong setting
PiOS CAN: Enable TX IRQ

This gets sending longer messages work properly.
PiOS CAN: remove led toggling
UAVORelay: tweak timings, seems to be required to work