Claude review: gpu: nova-core: add Architecture::uses_sec2() helper

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

Patch Review

**Purpose:** Extract the `matches!(self, Turing | Ampere | Ada)` check into a named method on `Architecture`, so it can be reused across boot and unload paths.

```rust
+    /// Returns `true` if this architecture uses SEC2 to boot GSP.
+    ///
+    /// Turing/Ampere/Ada use FWSEC + SEC2 booter firmware. Hopper and later use FSP instead.
+    pub(crate) const fn uses_sec2(&self) -> bool {
+        matches!(self, Self::Turing | Self::Ampere | Self::Ada)
+    }
```

And in `boot.rs`:
```rust
-        let uses_sec2 = matches!(
-            chipset.arch(),
-            Architecture::Turing | Architecture::Ampere | Architecture::Ada
-        );
+        let uses_sec2 = chipset.arch().uses_sec2();
```

**Observations:**

- **Good refactoring**: The doc comment clearly explains the hardware semantics. This is the right abstraction — it names the concept ("uses SEC2") rather than just listing architectures.

- **`const fn` with `&self`**: This works in modern Rust and is appropriate for a pure pattern match on an enum.

- **Negative-logic consideration**: The method defines the "old" path positively. An alternative would be something like `uses_fsp()` for the Hopper+ path, but `uses_sec2()` is arguably better since the SEC2 path is the one with more complex steps (FWSEC-SB, booter unloader), so guarding that behind the check is natural.

- **Future architectures**: When new architectures are added (e.g., Rubin), they will naturally not match `Turing | Ampere | Ada`, so `uses_sec2()` will return `false`. This is the correct default for Hopper-and-later GPUs. The exhaustive-match pattern in `Chipset::arch()` will force explicit handling when new chipsets are added.

**Verdict:** Clean, correct refactoring. No issues.

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Generated by Claude Code Patch Reviewer