Claude review: drm/msm/a6xx: Add support for Debug HFI Q

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

Adds a third HFI queue (Debug) for F2H messages from GMU firmware, useful for coredump debugging.

**Bug:** The WARN_ON check is off-by-one:
```c
WARN_ON(idx >= HFI_MAX_QUEUES);
```
At this point `idx` is 2 and `HFI_MAX_QUEUES` is 3, so `2 >= 3` is false — the WARN never fires. This check should be `WARN_ON(idx + 1 > HFI_MAX_QUEUES)` or should appear *after* the idx++ to catch overflow, or better yet, just use a `static_assert` or BUILD_BUG_ON at compile time since the array sizes are all compile-time constants. As written, the WARN_ON doesn't protect against anything.

**Note:** The HFI memory BO size should be verified — previously 2 queues at 4K each (8K within the HFI BO), now 3 queues needing 12K of payload space plus the table header. The BO allocation happens elsewhere and should be checked to be large enough.

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Generated by Claude Code Patch Reviewer