firmware: arm_scmi: Introduce devres get/put protocols operations

Expose to the SCMI drivers a new devres managed common protocols API
based on generic get/put methods and protocol handles.

All drivers still keep using the old API, no functional change.

Link: https://lore.kernel.org/r/20210316124903.35011-4-cristian.marussi@arm.com


Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>