[BUG] ASUS ROG Flow Z13 GZ302EA: ALC294 internal mic routing broken; ACP/PDM forced path unusable

### 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.
- [x] I have tried to reproduce the issue on Arch Linux's `linux` kernel.

### Upstream / vanilla kernel check

I have not tested with a vanilla/upstream kernel

### Kernel variant

linux-cachyos (EEVDF, Clang)

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

```text
cachyos-bugreport.sh hangs on my system. Manual information below.

Linux ai 7.0.11-1-cachyos #1 SMP PREEMPT_DYNAMIC Fri, 05 Jun 2026 09:37:35 +0000 x86_64 GNU/Linux

ROG Flow Z13 GZ302EA_GZ302EA
GZ302EA
ASUSTeK COMPUTER INC.
1.0
```

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

```text
ACP device:

c4:00.5 Multimedia controller [0480]: Advanced Micro Devices, Inc. [AMD] Audio Coprocessor [1022:15e2] (rev 70)
Subsystem: ASUSTeK Computer Inc. Device [1043:1fb3]
Kernel driver in use: snd_acp_pci
Kernel modules: snd_pci_acp3x, snd_rn_pci_acp3x, snd_pci_acp5x, snd_pci_acp6x, snd_acp_pci, snd_rpl_pci_acp6x, snd_pci_ps, snd_sof_amd_renoir, snd_sof_amd_rembrandt, snd_sof_amd_vangogh, snd_sof_amd_acp63, snd_sof_amd_acp70

ALSA cards:

0 [Generic ]: HDA-Intel - HD-Audio Generic
HD-Audio Generic at 0xa0448000 irq 156
1 [Generic_1 ]: HDA-Intel - HD-Audio Generic
HD-Audio Generic at 0xa0440000 irq 158

Capture devices:

**** List of CAPTURE Hardware Devices ****
card 1: Generic_1 [HD-Audio Generic], device 0: ALC294 Analog [ALC294 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0

Relevant loaded modules:

snd_acp70
snd_acp_pdm
snd_acp_i2s
snd_acp_pcm
snd_sof_amd_acp70
snd_pci_ps
snd_acp_pci
snd_amd_acpi_mach
snd_acp_legacy_common
snd_soc_acpi_amd_match
snd_hda_intel
snd_hda_codec_alc269
snd_hda_codec_realtek_lib
```

### Bug description

The internal microphone array on ASUS ROG Flow Z13 2025 GZ302EA does not appear as an ACP70/DMIC/PDM capture device.

The laptop has a built-in 3-microphone array according to ASUS specifications, but Linux only exposes the HDA/Realtek fallback path: ALC294 Analog.

The AMD ACP70 device is detected:

- PCI ID: 1022:15e2 rev 70
- Subsystem: 1043:1fb3
- Kernel driver in use: snd_acp_pci

ACP/PDM-related modules are loaded, including snd_acp70 and snd_acp_pdm, but no ACP/DMIC/PDM ALSA capture card is created.

Only this capture device is available:

card 1: Generic_1 [HD-Audio Generic], device 0: ALC294 Analog [ALC294 Analog]

This looks like missing ACP70/DMIC machine driver support or a missing quirk/match for ASUS GZ302EA / 1043:1fb3.

### Steps to reproduce

1. Boot ASUS ROG Flow Z13 2025 GZ302EA on linux-cachyos 7.0.11.
2. Run: lspci -nnk -s c4:00.5
3. Run: cat /proc/asound/cards
4. Run: arecord -l
5. Observe that ACP70 is detected, but only the HDA/Realtek ALC294 Analog capture device is exposed.

### Expected behavior

The internal 3-microphone array should be exposed as an ACP70/DMIC/PDM ALSA capture device, so PipeWire can use the real digital microphone array.

### Actual behavior

No ACP70/DMIC/PDM capture card is created.

Only the HDA/Realtek fallback capture device is available:

card 1: Generic_1 [HD-Audio Generic], device 0: ALC294 Analog [ALC294 Analog]

### Logs / stack traces

```text

```

### Additional system information

_No response_