set the clock on non-SDC installations

[aglarond]

My understanding from a comment made on the fix for OS-1126 is that the clock is set during setup on SDC installations. Keith suggested a separate bug be opened to address the clock being set on non-SDC installations.

The rationale for placing this in smartdc-config is the following:

1. the network/ntp service is dependent upon system/smartdc/config
2. smartdc-config already sets the ntp configuration
3. it seemed overkill to create a separate service to do the check and execute the command

- Dimitri