ALSA: usb-audio: Add quirk flag for Sennheiser MOMENTUM 3

The Sennheiser MOMENTUM 3 is a wireless around-ear headphones featuring
ANC, which can be connected via Bluetooth or USB-C.

When connecting via USB-C, its UAC mixer works fine and precisely
corresponds to the reported dB range. However, the mixer's volume
GET_CUR method is somehow stubbed and returns a constant value (15dB).
Since commit 86aa1ea ("ALSA: usb-audio: Do not expose sticky
mixers"), the sticky check considers the mixer to be sticky and
unnecessarily disables the mixer.

Add a quirk table entry matching VID/PID=0x1377/0x6004 and applying
the MIXER_GET_CUR_BROKEN quirk flag, so that the mixer is usable again.

Quirky device sample:

  usb 7-1.4.4.1.1.1: new full-speed USB device number 30 using xhci_hcd
  usb 7-1.4.4.1.1.1: New USB device found, idVendor=1377, idProduct=6004, bcdDevice=38.85
  usb 7-1.4.4.1.1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
  usb 7-1.4.4.1.1.1: Product: MOMENTUM 3
  usb 7-1.4.4.1.1.1: Manufacturer: Sennheiser electronic GmbH & Co. KG
  usb 7-1.4.4.1.1.1: SerialNumber: <REDACTED>
  usb 7-1.4.4.1.1.1: Found last interface = 0
  usb 7-1.4.4.1.1.1: 1:1: add audio endpoint 0x3
  usb 7-1.4.4.1.1.1: Creating new data endpoint #3
  usb 7-1.4.4.1.1.1: 1:1 Set sample rate 48000, clock 0
  usb 7-1.4.4.1.1.1: 6:0: sticky mixer values (0/11520/768 => 3840), disabling
  usb 7-1.4.4.1.1.1: [6] FU [PCM Playback Volume] skipped due to invalid volume
  input: Sennheiser electronic GmbH & Co. KG MOMENTUM 3 as /devices/pci0000:00/0000:00:08.3/0000:67:00.4/usb7/7-1/7-1.4/7-1.4.4/7-1.4.4.1/7-1.4.4.1.1/7-1.4.4.1.1.1/7-1.4.4.1.1.1:1.2/0003:1377:6004.002B/input/input208
  input: Sennheiser electronic GmbH & Co. KG MOMENTUM 3 Consumer Control as /devices/pci0000:00/0000:00:08.3/0000:67:00.4/usb7/7-1/7-1.4/7-1.4.4/7-1.4.4.1/7-1.4.4.1.1/7-1.4.4.1.1.1/7-1.4.4.1.1.1:1.2/0003:1377:6004.002B/input/input209
  hid-generic 0003:1377:6004.002B: input,hiddev99,hidraw12: USB HID v1.11 Device [Sennheiser electronic GmbH & Co. KG MOMENTUM 3] on usb-0000:67:00.4-1.4.4.1.1.1/input2

Signed-off-by: Rong Zhang <i@rong.moe>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260531-uac-quirk-get-cur-vol-v4-2-ede643dca151@rong.moe

Author: Rongronggg9

sound/usb/quirks.c

@@ -2357,6 +2357,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
 		   QUIRK_FLAG_FORCE_IFACE_RESET | QUIRK_FLAG_IFACE_DELAY),
 	DEVICE_FLG(0x1224, 0x2a25, /* Jieli Technology USB PHY 2.0 */
 		   QUIRK_FLAG_GET_SAMPLE_RATE | QUIRK_FLAG_MIC_RES_16),
+	DEVICE_FLG(0x1377, 0x6004, /* Sennheiser MOMENTUM 3 */
+		   QUIRK_FLAG_MIXER_GET_CUR_BROKEN),
 	DEVICE_FLG(0x1395, 0x740a, /* Sennheiser DECT */
 		   QUIRK_FLAG_GET_SAMPLE_RATE),
 	DEVICE_FLG(0x1397, 0x0507, /* Behringer UMC202HD */