Claude review: drm/panthor: Store IRQ register base iomem pointer in panthor_irq

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

Patch Review

**Status: Good, with one minor observation.**

Adds `void __iomem *iomem` to `struct panthor_irq` and introduces generic IRQ register offset defines:

```c
+#define INT_RAWSTAT		0x0
+#define INT_CLEAR		0x4
+#define INT_MASK		0x8
+#define INT_STAT		0xc
```

The `PANTHOR_IRQ_HANDLER` macro signature simplifies from `(__name, __reg_prefix, __handler)` to `(__name, __handler)` — the per-block `__reg_prefix` (e.g., `GPU_INT_`, `JOB_INT_`, `MMU_INT_`) is no longer needed because each IRQ instance now carries its own iomem base pointing to the right register block.

The IRQ request functions gain an `iomem` parameter:

```c
-int panthor_request_gpu_irq(struct panthor_device *ptdev, ...);
+int panthor_request_gpu_irq(struct panthor_device *ptdev,
+			    void __iomem *iomem, ...);
```

**Observation:** The names `INT_RAWSTAT`, `INT_CLEAR`, `INT_MASK`, `INT_STAT` are quite generic. They're defined in `panthor_device.h` which is only included within the panthor driver, so namespace collision risk is low in practice. But if this header ever gets transitively included from a broader context, these names could clash. A `PANTHOR_` prefix might be safer, though this is a minor style point and not a blocking issue.

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Generated by Claude Code Patch Reviewer