firmware: arm_scmi: Add bound iterators support

firmware: arm_scmi: Add bound iterators support

SCMI core stack provides some common helpers to handle in a unified way
multipart message replies: such iterator-helpers, when run, currently
process by default the whole set of discovered resources.

Introduce an alternative way to run the initialized iterator on a limited
range of resources.

Note that the subset of resources that can be chosen is anyway limited by
the SCMI protocol specification, since you are only allowed to choose the
start-index on a multi-part enumeration NOT the end-index, so that the
effective number of returned items by a bound iterators depends really
on platform side decisions.

Suggested-by: Etienne Carriere <etienne.carriere@foss.st.com>
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260508153300.2224715-11-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>