Implement the following PHC operations:
1. adjtime - for adding an offset to the PHC clock time.
2. adjfine - for adjusting the PHC clock frequency.
3. gettime64 - for getting the PHC clock time. This function returns
   the time as adjusted by adjtime and adjfine.

The adjusted time will also be used for time sync frames timestamping.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.f59750deeee4.I110a7e3ac3c6d39d9dbe1fe77001e3f5bc3814eb@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>