Is your feature request related to a problem? Please describe.
Since 2022, SOF has been moving to Zephyr as its primary RTOS with work tracked in #5794
Most SOF users have either completed the transition to Zephyr, or are in progress of adding support for Zephyr for their platforms.

This ticket is for removal of XTOS support from SOF main, leaving XTOS support only supported in release stable branches. There is a set of cleanups we can proceed with, once XTOS support is removed, so having a ticket to mark as a dependency is useful for tracking.

Describe the solution you'd like
XTOS support removal from "main" branch

Feature Breakdown
This feature cannot be performed as a single large PR as we have many platforms, drivers, features and abstractions based around the legacy xtos code and this means we will need to remove section by section and make any necessary adaptations as needed for each removal.

These lists are not exhaustive, but the starting point for xtos removal.

Xtos Platform removals

• Intel - platform headers and some platform drivers remain for Intel platforms.
• NXP - platform headers and some drivers remain for NXP platforms.
• AMD - platform headers and some drivers remain for AMD platforms.
• MTK - platform headers and some drivers remain for MTK platforms.

Xtos Peripheral Driver removals

• Intel - DMA drivers remain for Intel platforms.
• NXP - DMA, SAI, IPC drivers remain for NXP platforms.
• AMD - DAI, DMA, interrupt drivers remain for AMD platforms.
• MTK - DAI, DMA, interrupt drivers remain for MTK platforms.

Xtos Feature/abstraction removals

• DMA interface.
• Clock API
• IPC API.
• coherent API.
• wait API
• C library duplications.
• trace API