ALSA: usb-audio: Add native DSD quirks for PureAudio DAC series

ALSA: usb-audio: Add native DSD quirks for PureAudio DAC series

The PureAudio APA DAC and Lotus DAC5 series are USB Audio
2.0 Class devices that support native Direct Stream Digital (DSD)
playback via specific vendor protocols.

Without these quirks, the devices may only function in standard
PCM mode, or fail to correctly report their DSD format capabilities
to the ALSA framework, preventing native DSD playback under Linux.

This commit adds new quirk entries for the mentioned DAC models
based on their respective Vendor/Product IDs (VID:PID), for example:
0x16d0:0x0ab1 (APA DAC), 0x16d0:0xeca1 (DAC5 series), etc.

The quirk ensures correct DSD format handling by setting the required
SNDRV_PCM_FMTBIT_DSD_U32_BE format bit and defining the DSD-specific
Audio Class 2.0 (AC2.0) endpoint configurations. This allows the ALSA
DSD API to correctly address the device for high-bitrate DSD streams,
bypassing the need for DoP (DSD over PCM).

Test on APA DAC and Lotus DAC5 SE under Arch Linux.

Tested-by: Lushih Hsieh <bruce@mail.kh.edu.tw>
Signed-off-by: Lushih Hsieh <bruce@mail.kh.edu.tw>
Link: https://patch.msgid.link/20251114052053.54989-1-bruce@mail.kh.edu.tw
Signed-off-by: Takashi Iwai <tiwai@suse.de>