intel_cvs: Critical for IPU7 camera on Panther Lake - should be upstreamed to mainline

## Summary

The `intel_cvs` driver from this repo is **required** to get the IPU7 camera working on Intel Panther Lake laptops (e.g., Dell XPS) running mainline kernels (tested on 7.0-rc7). Without it, the ACPI dependency chain for the OV08X40 sensor is never satisfied and the sensor I2C device is never created.

## Details

On Dell Panther Lake with the Synaptics SVP7500 USBIO bridge, the camera sensor (OVTI08F4 / OV08X40) has an ACPI dependency on CVSS (INTC10E1), which is handled by `intel_cvs`. The dependency chain is:

```
LNK1 (sensor) → CVSS (intel_cvs) + DSC1 + VIC1 (i2c_usbio)
```

Without `intel_cvs` loaded, the kernel never creates the sensor's I2C device, and IPU7 ISYS reports "no sensors available."

## Current state

- IPU7 ISYS is in-tree since kernel 6.17
- `intel_cvs` is **not** in-tree and must be built manually from this repo
- Must be built with `CC=clang LLVM=1` on clang-built kernels (e.g., CachyOS)
- Must be rebuilt after every kernel update

## Request

Please consider upstreaming `intel_cvs` to the mainline kernel. It's a critical piece of the IPU7 camera stack and currently the #1 blocker for getting webcams working on Panther Lake laptops running mainline or Arch-based distros.

## Workaround

I've written a complete guide for getting the IPU7 camera working on CachyOS/Arch with the software ISP path:
https://www.reddit.com/r/cachyos/ (search for "IPU7 camera guide")

## Environment

- Dell XPS with Intel Panther Lake
- CachyOS, kernel 7.0.0-rc7-2-cachyos-rc
- Sensor: OV08X40 (OVTI08F4)
- Bridge: Synaptics SVP7500 USBIO