Add micro-ecc port definition specification

[jarekfoh]

YT: ISC-260

Description

Added micro-ecc library to ports.

Motivation and Context

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (refactoring, style fixes, git/CI config, submodule management, no code logic changes)

How Has This Been Tested?

• Already covered by automatic testing.
• New test added: (add PR link here).
• Tested by hand on: armv8m33-mcn94x-frdm, ia32-generic-pc, armv7m4-stm32l4x6-nucleo.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing linter checks and tests passed.
• My changes generate no new compilation warnings for any of the targets.

Special treatment

• This PR needs additional PRs to work (list the PRs, preferably in merge-order).
• I will merge this PR by myself when appropriate.

[gemini-code-assist]

Code Review

This pull request adds a new port definition file micro-ecc/port.def.sh for the micro-ecc library. The feedback recommends addressing style inconsistencies by using tabs instead of spaces for indentation, appending a trailing slash to src_path to match project conventions, and using cp -a instead of cp for more robust file copying.