When SCMI raw coexistence mode is enabled make the core stack probe
successfully even when the initial base protocol exchanges with the
platform/server failed.

This behaviour enables the system to boot with a broken regular SCMI
stack but with a fully functional and accessible SCMI raw debugfs
interface that can be used to further debug the issue.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20230223152330.2707260-1-cristian.marussi@arm.comSigned-off-by: Sudeep Holla <sudeep.holla@arm.com>