Split the three different uxBits checks in the PMIC task. The only significant
difference occurs if the SAMPLE_RATE and CHAREG_STATE event flags are both set
simultaneously. Previously only the SAMPLE_RATE bit would be handled and cleared
for this case, now both will be processed. I don't know whether this makes a
difference in practice but it appears cleaner.
Merge pull request #118 from jburgess777/pmic-task-split-event-handling

Split the three different uxBits checks in the PMIC task.