- Set DCO calibrate target back to 4096 binary kHz

- Set DCO calibrate target back to 4096 binary kHz
- Add new command/event in Msp430ClockInit to enable overriding of the startup values for the DCO calibrate routine
- Modify PlatformC/PlatformP in platform/telosa to use intermediate configuration MoteClockC that can be used to override the default clock initialization via MoteClockP
- Add MoteClockC and MoteClockP in platform/telosb to allow for usage of the DCOR flag / ROSC on tmote sky. The overriding configuration is currently disabled pending closer review of the calibration routine behavior for the new setup and other potential gotchas