ice: add admin commands to access cgu configuration

ice: add admin commands to access cgu configuration

Add firmware admin command to access clock generation unit
configuration, it is required to enable Extended PTP and SyncE features
in the driver.
Add definitions of possible hardware variations of input and output pins
related to clock generation unit and functions to access the data.

Signed-off-by: Arkadiusz Kubalewski <[email protected]>
Signed-off-by: Vadim Fedorenko <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>