audio/topology: add multi-KPB WOV arbiter for 3-keyword DMIC capture

Adds a new WOV arbiter component and multi-KPB topology to support three
simultaneous wake-word detectors sharing a single DMIC, with exclusive
host PCM drain arbitration when any keyword fires.

New component: src/audio/wov_arbiter/
- 3 input pins (one per KPB host-sink), 1 output pin (to host copier)
- AMS subscriber for AMS_WOV_DETECT_MSG_UUID: activates the triggering
  slot and broadcasts WOV_CTRL PAUSE to sibling detectors
- On trigger(STOP): deactivates and broadcasts WOV_CTRL RESUME so all
  detectors return to listening
- Idle inputs are silently drained to prevent buffer stalls
- UUID 4a5b6c7d-8e9f-4a1b-2c3d-4e5f60718293 registered in uuid-registry

AMS additions (ams_msg.h):
- AMS_WOV_DETECT_MSG_UUID: detector -> arbiter on keyword detect
- AMS_WOV_CTRL_MSG_UUID:   arbiter -> detectors for pause/resume control

detect_test extensions:
- IPC4_DETECT_TEST_SET_WOV_SLOT large-config param assigns a slot id (0-2)
- On detection: also sends AMS_WOV_DETECT_MSG_UUID with slot_id to arbiter
- AMS consumer for WOV_CTRL: sets paused flag; copy() drains buffer
  without running the detector when paused
- The existing energy-threshold detector fires on a hand clap, making
  detect_test a ready-to-use lab test stub for this topology

Topology: tools/topology/topology2/platform/intel/dmic-wov-multi.conf
- Pipeline 100 (Core 0): DMIC Copier -> Mixin (fan-out to 3 Mixouts)
- Pipelines 101-102 (Core 0): Mixout -> KPB -> detect_test (slots 0-1)
- Pipeline 103 (Core 1): Mixout -> KPB -> detect_test (slot 2)
- Pipeline 104 (Core 0): WOV Arbiter -> Host Copier (single PCM stream)
- KPB output_pin_binding: pin 0 -> detector (sel_sink),
                          pin 1 -> arbiter (host_sink)

Requires: CONFIG_COMP_WOV_ARBITER, CONFIG_COMP_KPB, CONFIG_COMP_MIXIN_MIXOUT,
          CONFIG_AMS, CONFIG_COMP_KWD_DETECT

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: lrgirdwo

src/audio/CMakeLists.txt

@@ -107,6 +107,9 @@ if(NOT CONFIG_COMP_MODULE_SHARED_LIBRARY_BUILD)
 	if(CONFIG_COMP_VOLUME)
 		add_subdirectory(volume)
 	endif()
+	if(CONFIG_COMP_WOV_ARBITER)
+		add_subdirectory(wov_arbiter)
+	endif()
 	if(CONFIG_DTS_CODEC)
 		add_subdirectory(codec)
 	endif()

src/audio/Kconfig

@@ -102,6 +102,18 @@ config COMP_STUBS
 	  Select to force all 3P blocks to link against stubs rather than their libraries. This
 	  should only be used in testing environments like fuzzers or CI.
 
+config COMP_WOV_ARBITER
+	bool "WOV arbiter component"
+	depends on COMP_KPB
+	depends on IPC_MAJOR_4
+	select AMS
+	help
+	  Select to build the WOV (Wake-on-Voice) arbiter.  The arbiter sits
+	  between multiple KPB host-drain outputs and a single host PCM copier.
+	  When a keyword is detected by one of the WOV detectors the arbiter
+	  routes that KPB's drain stream to the host and instructs the remaining
+	  detectors to pause.
+
 config COMP_KPB
 	bool "KPB component"
 	default y

src/audio/wov_arbiter/CMakeLists.txt

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: BSD-3-Clause
+
+add_local_sources(sof wov_arbiter.c)