arm_mpam: Add a helper to touch an MSC from any CPU

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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Resetting RIS entries from the cpuhp callback is easy as the
callback occurs on the correct CPU. This won't be true for any other
caller that wants to reset or configure an MSC.

Add a helper that schedules the provided function if necessary.
Prevent the cpuhp callbacks from changing the MSC state by taking the
cpuhp lock.

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