[BUG] ASUS ProArt PX13 HN7306EA - No sound (AMD ACP70 no playback device)

### Pre-flight checklist

- [x] I have searched existing issues and this is not a duplicate.
- [x] I have read the [Contributing Guidelines](https://github.com/CachyOS/linux-cachyos/blob/master/CONTRIBUTING.md).
- [x] I have verified the issue is reproducible with the latest available CachyOS kernel.

### Upstream / vanilla kernel check

I was unable to test with a vanilla/upstream kernel

### Kernel variant

linux-cachyos (EEVDF, Clang)

### System information (cachyos-bugreport.sh)

```text
https://paste.cachyos.org/p/3ccdbcb.log
```

### Manual system information (if cachyos-bugreport.sh is unavailable)

```text

```

### Bug description

**Hardware:** ASUS ProArt PX13 HN7306EA (AMD Ryzen AI MAX+ 395)
**OS:** CachyOS 6.19.3-2-cachyos
**Kernel:** 6.19.3-2-cachyos

## Issue Summary

Fresh CachyOS install could not boot. After adding `iommu=pt` kernel parameter, system boots but has no sound.

## Boot Issue (Workaround Found)
- Error on fresh boot: `AMD-Vi: Event: logged IO_PAGE_FAULT`
- Fix: Add `iommu=pt` to kernel parameters

## Audio Issue
- Internal speakers do not work
- No playback device created for AMD ACP70 audio

## Verification

```
$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Generic [HD-Audio Generic], device 3: HDMI 0 [HDMI 0]
(no playback on card 1)
```

```
$ cat /proc/asound/cards
0 [Generic ]: HDA-Intel - HD-Audio Generic
HD-Audio Generic at 0xa0440000 irq 161
1 [acppdmmach ]: acp-pdm-mach - acp-pdm-mach
ASUSTeK COMPUTERINC.-ProArtPX13HN7306EA-1.0-HN7306EA
```

Card 1 (AMD ACP70) has no playback device, only DMIC capture exists.

### Steps to reproduce

1. Install CachyOS on ASUS ProArt PX13 HN7306EA laptop
2. Attempt to boot (fresh install)
3. System fails to boot with error: AMD-Vi: Event: logged IO_PAGE_FAULT
4. Add iommu=pt kernel parameter to boot (workaround for boot issue)
5. System boots successfully but has no sound

### Expected behavior

Internal speakers should work like other AMD Strix Halo laptops.

### Actual behavior

No sound output from internal speakers

### Logs / stack traces

```text

```

### Additional system information

_No response_