Adding j2c+ platforms for supporting NOKIA devices in GCU validator

[okaravasi]

Currently file generic_config_updater/gcu_field_operation_validators.conf.json is used from test cases to verify if the platform under test allowes updates to config paths:

/PFC_WD /BUFFER_POOL /BUFFER_PROFILE /WRED_PROFILE

Currently pltaforms for j2c+ chips are not included with as a result the tests report erroneously status for the relevant test cases that verify these paths. The current PR adds these platforms to support testing on this paths also as expected. More specifically a new entry for j2c+ chips was added under broadcom entry. For this new entry, 2 NOKIA hwskus are added.

What I did

How I did it

How to verify it

Ran existing GCU tests in newly added platforms and verified that the test pass. Ran also in differnet platform than the added and verified there are no unexpecetd failures.

Previous command output (if the output of a command-line utility has changed)

New command output (if the output of a command-line utility has changed)