firmware: arm_scmi: Harden accesses to the reset domains

commit e9076ffbcaed5da6c182b144ef9f6e24554af268 upstream.

Accessing reset domains descriptors by the index upon the SCMI drivers
requests through the SCMI reset operations interface can potentially
lead to out-of-bound violations if the SCMI driver misbehave.

Add an internal consistency check before any such domains descriptors
accesses.

Link: https://lore.kernel.org/r/20220817172731.1185305-5-cristian.marussi@arm.com


Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>