ucm2: codecs: add rt721+rt1320 companion init configuration

ucm2: codecs: add rt721+rt1320 companion init configuration

[GitHub pull_request - opened]

alsa-project/alsa-ucm-conf pull request #852 was opened from sri-sandeep108:

Add `ucm2/codecs/rt721+rt1320/init.conf` to support machines using the Realtek RT721 + RT1320 companion amplifier combination on `sof-soundwire`.

### Problem
When the kernel SoundWire driver detects RT721 and RT1320, it emits the combined component token `spk:rt721+rt1320`.
In `sof-soundwire.conf`, `SpeakerCodecFile` remains `rt721+rt1320`. When attempting to include `/codecs/${var:SpeakerCodecFile}/init.conf`, UCM fails because `/usr/share/alsa/ucm2/codecs/rt721+rt1320/init.conf` does not exist, causing the entire soundcard use case configuration import to fail (`-2`).

### Solution
Provide `ucm2/codecs/rt721+rt1320/init.conf`. RT721 initialization is handled through `codecs/rt721/init.conf` (via the headset branch), and RT1320 mixer controls are managed directly by `sof-soundwire/rt721+rt1320.conf`.

### Verification
Tested on Lenovo Yoga Pro 7 15IPH11 (`83SN`, Intel Core Ultra Panther Lake with RT721 + RT1320). UCM imports successfully, exposing HiFi playback on speakers, headphones, and multi-channel DMIC capture.

Closes: https://github.com/alsa-project/alsa-ucm-conf/issues/851
Fixes: 196b79b04126 ("sof-soundwire: add companion amp config with rt721 and rt1320")
Signed-off-by: Sri Sandeep Sakthivel <sandyorton7@gmail.com>

Request URL   : https://github.com/alsa-project/alsa-ucm-conf/pull/852
Patch URL     : https://github.com/alsa-project/alsa-ucm-conf/pull/852.patch
Repository URL: https://github.com/alsa-project/alsa-ucm-conf