Subject: 7060x6-64pe 256x100g support

[ccroy-arista]

Why I did it

Baseline implementation for 256x100g support in the Arista-7060X6-64PE (DCS-7060X6-64PE) has been requested by MSFT.

Work item tracking

• Microsoft ADO (number only):

How I did it

Added the necessary files for baseline implementation of 256x100g implementation for Quicksilver OSFP.

How to verify it

Sanitize DUT with this change and confirm that the relevant interfaces are up.

Which release branch to backport (provide reason below if selected)

• [ ] 201811
• [ ] 201911
• [ ] 202006
• [ ] 202012
• [ ] 202106
• [ ] 202111
• [ ] 202205
• [ ] 202211
• [ ] 202305
• [x] 202405

Tested branch (Please provide the tested image version)

master

Description for the changelog

Baseline support for the Arista-7060X6-64PE-256x100G platform variant.

A picture of a cute animal (not mandatory but encouraged)

[ccroy-arista]

/azpw ms_conflict

[r12f]

Chris to update this, early this week.

We will ignore the non-used ports, but not making the port number contiguous.

[StormLiangMS]

@bingwang-ms could you take for 202405? TH5.

[mssonicbld]

Cherry-pick PR to 202405: https://github.com/sonic-net/sonic-buildimage/pull/20463