cpufreq: CPPC: keep target core awake when reading its cpufreq rate

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I73EPL



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As ARM AMU's document says, all counters are subject to any changes
in clock frequency, including clock stopping caused by the WFI and WFE
instructions.

Therefore, using smp_call_on_cpu() to trigger target CPU to
read self's AMU counters, which ensures the counters are working
properly during calculation.

Signed-off-by: Zeng Heng <zengheng4@huawei.com>