[FEATURE] exception handler roadmap. #6743

Today exception handlers spin the DSP and emit an IPC error. We can do better. (pls add other items here)

• Call Zephyr stack and context dump
• Write stack and context to SRAM Window (and power SRAM ON if OFF)
• Inform host and include any SOF application context error token (@aborisovich I'm calling this an error token today as I dont have a better name). This will depend on your error code work.
• Put the DSP into a recoverable state (e.g. mask, IRQ, stop timers, disable DMAs) so that host can reload FW or reboot without a power cycle.
• Invoke the GDB stub in polling mode (if in debug mode) - this allows further FW introspection

@thesofproject/steering-committee @kv2019i @nashif @andyross @mmaka1 @marcinszkudlinski