arm64: dts: juno: Update SCPI nodes as per the YAML schema

The SCPI YAML schema expects standard node names for clocks and
power domain controllers. Fix those as per the schema for Juno
platforms.

Link: https://lore.kernel.org/r/20210608145133.2088631-1-sudeep.holla@arm.com


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