firmware: arm_scmi: Add support for clock parents

SCMI v3.2 spec introduces CLOCK_POSSIBLE_PARENTS_GET, CLOCK_PARENT_SET
and CLOCK_PARENT_GET. Add support for these to enable clock parents
and use them in the clock driver.

Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20231004-scmi-clock-v3-v5-1-1b8a1435673e@nxp.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>