arm64: dts: Update cache properties for marvell

The DeviceTree Specification v0.3 specifies that the cache node
'compatible' and 'cache-level' properties are 'required'. Cf.
s3.8 Multi-level and Shared Cache Nodes

The recently added init_of_cache_level() function checks
these properties. Add them if missing.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>