[SensorData] -- Reorder struct to improve byte packing and save
unnecessary padding especially for large arrays
(e.g., synchronizer). Can save ~7kB for the ImuCal nanoapp.

Base Memory
text    data   bss     dec
26012   3108   29432   58552

New Memory
text    data   bss     dec
25788   3004   23032   51824

Change-Id: I5f1d35cdec90c834854fa3fb3be45ede38ab4426
Head: 230936402
Test: Unit Test
1 file changed