SCMI transport based on Mailbox

configname: CONFIG_ARM_SCMI_TRANSPORT_MAILBOX

Linux Kernel Configuration
└─>Device Drivers
└─>Firmware Drivers
└─>ARM System Control and Management Interface Protocol
└─>SCMI transport based on Mailbox
In linux kernel since version 5.2 (release Date: 2019-07-07)  
Enable mailbox based transport for SCMI.

If you want the ARM SCMI PROTOCOL stack to include support for a
transport based on mailboxes, answer Y.