mm: Unified memory management alignment length

[W-M-R]

Note: Please adhere to Contributing Guidelines.

Summary

mm: Unified memory management alignment length

Impact

Update this section, where applicable, on how change affects users,
build process, hardware, documentation, security, compatibility, etc.

Testing

Update this section with details on how did you verify the change,
what Host was used for build (OS, CPU, compiler, ..), what Target was
used for verification (arch, board:config, ..), etc. Providing build
and runtime logs from before and after change is highly appreciated.

[nuttxpr]

[Experimental Bot, please feedback here]

This PR appears incomplete and does not fully meet the NuttX requirements. While it provides a title under the Summary section, it lacks crucial details about the change's necessity, functionality, and related issues. The Impact and Testing sections are essentially placeholders, asking for information rather than providing it.

Here's a breakdown of what's missing:

• Summary: Needs a thorough explanation of the why, what, and how of the change. References to related issues are also missing. Just stating "Unified memory management alignment length" is insufficient. What was the previous behavior? What problem does this solve? What is the new alignment length?
• Impact: The placeholder text needs to be replaced with concrete information. Every bullet point should have a "YES" or "NO" followed by a description if applicable. Even if the answer is "NO," it should be explicitly stated.
• Testing: This section requires specific details about the testing environment and the results. Simply requesting the information isn't enough. The user needs to fill in the build host, target details, and importantly, the actual testing logs from before and after the change. Without these logs, there's no evidence that the change works as intended.

Therefore, before this PR can be considered, the author needs to substantially revise it by providing the missing details in all three sections (Summary, Impact, and Testing). Simply replacing placeholders with "NO" is not enough; a proper justification is needed for each item.