Reduce the size of the Rock S0 CMA to match Rock PI-S + include fixMACaddress script

[brentr]

in the S0 image to assign end0 MAC address from CPU serial #
in case running U-Boot earlier than 2024.10

Description

Correct misleading comments in /etc/udev/rules.d/05-fixMACaddress.rules
Add fixMACaddress script to Rock S0 image

Jira

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also note any relevant details for your test configuration.

• build and verified new S0 image still works and contains fixMACaddress script

Checklist:

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• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

[brentr]

@paolosabatino
Could you please review this?
I've added the CMA reduction to the S0. The performance hit is hard to quantify, so, for now, we'll stick withe the 16MB size. (The increase in free RAM is very quantifiable)