sw64: fix CPUFreq bug

Sunway inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5PNC3



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Dynamic frequency scaling cannot change the current cpu frequency
when userspace policy is used, and cpuinfo_cur_freq always displays
the default value. This patch fixes it.

Signed-off-by: Tang Jinyang <tangjinyang@wxiat.com>
Signed-off-by: Gu Zitao <guzitao@wxiat.com>