Fix incorrect BX assignment in LPM DAQ packet

Seth Cooper reported that the currently installed version of the LPM firmware at P5 shows an offset of the BX number in the LPM event fragment of -2 BX. As in: the correct BX number is 75, but the LPM event fragment shows 73.

This is reproducible in the B14 lab. The CPM event fragment looks okay though.

This feature is probably due to the work in the LPM firmware on cleaning up the orbit signal generation and monitoring. It needs to be fixed in software though (by changing the adjustment values).