[AMD SoundWire] Add DMI support for ASUS Vivobook S14 M3407GA (Realtek RT721 codec)

[bulltarddarcy]

Describe the bug
On the ASUS Vivobook S14 M3407GA, the physical Realtek RT721 codec is successfully detected on the SoundWire bus (sdw:0:1:025d:0721:01), but built-in speakers and the headphone jack are non-functional. The ALSA machine driver (snd-acp-sdw-mach) does not recognize the board because the Vivobook S14 M3407GA product name string is missing from its DMI match table.

What I've tried:

• Verified SoundWire device detection via /sys/bus/soundwire/devices/.
• Tested loading alternative machine/SOF modules (snd-acp-sdw-legacy-mach, snd-sof-amd-acp70).
• Updated to the latest HWE Edge kernel (7.0.0-28), but the card still fails to bind (aplay -l only lists HDMI outputs).

To Reproduce

1. Boot Linux on an ASUS Vivobook S14 M3407GA laptop.
2. Run ls /sys/bus/soundwire/devices/ to confirm the RT721 codec is present.
3. Run aplay -l and observe the absence of internal audio/speaker devices.

Reproduction Rate
10/10 (Always / 100% consistent across reboots and kernel updates).

Expected behavior
The snd-acp-sdw-mach driver should automatically match the DMI product name and bind the Realtek RT721 codec so built-in speakers and headphones work out of the box.

Impact
Showstopper (Zero internal audio functionality; requires external USB/Bluetooth audio workarounds).

Environment

1. Branch name and commit hash of the 2 repositories: sof (firmware/topology) and linux (kernel driver).

• Kernel: 7.0.0-28-generic (Ubuntu/Linux Mint HWE Edge)
• SOF: Upstream default provided by kernel package

2. Name of the topology file

• Topology: Default standard AMD SoundWire topology

3. Name of the platform(s) on which the bug is observed.

• Platform: AMD Ryzen / ASUS Vivobook S14 M3407GA

Screenshots or console output

jellyfish@jellyfish-vivobook:~$ ls /sys/bus/soundwire/devices/
sdw:0:1:025d:0721:01 sdw-master-0-0 sdw-master-0-1

jellyfish@jellyfish-vivobook:~$ cat /sys/class/dmi/id/product_name
Vivobook S14 M3407GA

jellyfish@jellyfish-vivobook:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Generic [HD-Audio Generic], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Generic [HD-Audio Generic], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Generic [HD-Audio Generic], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0