doc: api: add telemetry, logging, probes, and debug streams reference page

[lgirdwood]

Summary

Add a dedicated Telemetry, Logging & Probes C API reference page (api/telemetry.rst) and integrate it into api/index.rst.

Architecture & Overview

SOF features a multi-tiered diagnostic and telemetry subsystem. This PR documents the four architectural domains and integrates their Doxygen API definitions via Breathe:

1. Host DMA Tracing & Dictionary Logging (trace_logging_api):
   • Circular host DMA trace buffers (dma-trace.h), runtime logging filters and dictionary encoder (trace-soflogger.h), boot checkpoint codes (trace-boot.h), and panic crash dumps (ipc/trace.h).
2. Audio Probes & Stream Tap Points (audio_probe_api):
   • Pipeline buffer extraction and injection probes (probe/probe.h), extraction frame format framing (0xBABEBEBA, ipc/probe_dma_frame.h), and IPC commands (ipc3/probe.h).
3. Hardware Telemetry & Performance Monitoring (telemetry_perf_api):
   • Real-time CPU cycle accounting and execution metrics (telemetry.h), Memory Window 3 Performance Measurement Window (WIN3_MBASE, ADSP_PMW, performance_monitor.h), and SRAM Window 0 firmware status registers (kernel/mailbox.h).
4. Abstract Debug Streams & Low-Level Debugging (debug_stream_api):
   • Structured packet framing (DEBUG_STREAM_IDENTIFIER 0x1ED15EED, user/debug_stream.h), Memory Window 2 debug slots (user/debug_stream_slot.h), text debug messages (user/debug_stream_text_msg.h), and GDB target stub (sof/debug/gdb/gdb.h).

Diagrams Included

• DSP Firmware Trace Pipeline: Flowchart tracking log filtering, trace ring buffer queuing, host stream DMA, and user-space dictionary decoding.
• Audio Probe Tap Points: Diagram illustrating extraction and injection probe attachments to pipeline interconnect buffers.
• Shared SRAM Mailbox Layout: Memory map detailing Windows 0 (FSR/Mailbox), 1 (IPC), 2 (Debug Slots & Telemetry), and 3 (Performance Monitoring / PMW).

Verification

• Builds cleanly with SPHINXOPTS="-W --keep-going" make html with 0 errors and 0 warnings.
• Tested against the upstream SOF Doxygen XML tree from doc: telemetry: comprehensive Doxygen documentation for telemetry, logging, probes, and debug streams sof#11311.