Allow SCMI Raw mode coexistence with normal SCMI stack

configname: CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX

Linux Kernel Configuration
└─>Device Drivers
└─>Firmware Drivers
└─>ARM System Control and Management Interface Protocol
└─>Allow SCMI Raw mode coexistence with normal SCMI stack
In linux kernel since version 6.3 (release Date: 2023-04-23)  
Allow SCMI Raw transmission mode to coexist with normal SCMI stack.

This will allow regular SCMI drivers to register with the core and
operate normally, thing which could make an SCMI test suite using the
SCMI Raw mode support unreliable. If unsure, say N.