Claude review: firmware: qcom_scm: Migrate to generic PAS service

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

Patch Review

This refactors the existing SCM PAS functions into `__`-prefixed static functions that take a `struct device *dev` parameter (instead of using the global `__scm->dev`), then wires them up as a `qcom_pas_ops` backend. The old exported wrappers are kept as thin redirectors for the transition period.

**Observation on cast pattern:**

```c
return (struct qcom_scm_pas_context *)ctx;
```

The `qcom_scm_pas_context` and `qcom_pas_context` structs are layout-identical, so this is safe, but it's a maintenance hazard. This is cleaned up in patch 15, so it's acceptable as a transitional step. The intermediate naming (`__qcom_scm_pas_init_image2`, `__qcom_scm_pas_get_rsc_table2`) is a bit awkward but is similarly cleaned up later.

**Registration during probe:**

```c
if (qcom_scm_is_pas_available()) {
    qcom_pas_ops_scm.dev = scm->dev;
    qcom_pas_ops_register(&qcom_pas_ops_scm);
}
```

Setting `.dev` on a static struct just before registering works, but the non-atomicity of the two-step (set `.dev`, then register) is fine here since there's only one SCM platform device.

No functional issues.

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Generated by Claude Code Patch Reviewer