externalClockPort is not configurable in most implementations

[openBackhaul]

Problem:
The externalClockPort attribute is not configurable in most implementations.

Decision during the LF ONMI x-haul meeting on 17th of December 2025:

Making the following changes to the Synchronization modelling:

• Adding a read-only SyncLpSpec :: configurationOfExternalClockPortIsAvail : Boolean = false capability attribute with comment "If true, the externalClockPort attribute allows to configure the type of synch port."

• Amending the comment at the SyncLpSpec :: externalClockPort attribute with the following formulation "The externalClockPort attribute is indicating the synch port to be either of type 2MHz/2Mbit (if true) or traffic port (if false)."

[niloda]

I formally approve the resolution for this issue.
There are no objections to promoting the proposal to a final solution during the meeting on December, 17th.