Claude review: drm/connector: hdmi: Add support for 'link bpc' property

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

Patch Review

This patch is clean and straightforward.

**Setting link_bpc during atomic check:**

```c
		new_conn_state->link_bpc = new_conn_state->hdmi.output_bpc;
```

This sets `link_bpc` from `output_bpc` during `drm_atomic_helper_connector_hdmi_check()`. The `output_bpc` is computed during check and represents the negotiated bpc after bandwidth constraints. This is the correct place to set it for HDMI connectors using the helper framework.

**Automatic attachment in drmm_connector_hdmi_init:**

```c
	ret = drm_connector_attach_link_bpc_property(connector, max_bpc);
	if (ret)
		return ret;
```

Return value is properly checked here. Good.

**One consideration:** When the CRTC is disabled (no `new_conn_state->crtc`), `link_bpc` is not explicitly set to 0 or any sentinel value. The `else` branch of the check doesn't touch `link_bpc`, so it retains whatever value was in the old state (or the default 0). This means that on disconnect, the property won't be updated (the commit_tail check compares old vs new, and if they're the same, it won't fire). This seems acceptable but could be documented.

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Generated by Claude Code Patch Reviewer