cacheinfo: Expose the code to generate a cache-id from a device_node

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot/v6.7-rc2



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The MPAM driver identifies caches by id for use with resctrl. It
needs to know the cache-id when probeing, but the value isn't set
in cacheinfo until device_initcall().

Expose the code that generates the cache-id. The parts of the MPAM
driver that run early can use this to set up the resctrl structures.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Zeng Heng <zengheng4@huawei.com>