platform/x86/intel/uncore-freq: Display uncore current frequency

mainline inclusion
from mainline-v5.18-rc1
commit 414eef27
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I78KDD
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=414eef27283a2133a0998beb8e3e35f84eaac961



Intel-SIG: commit 414eef27  platform/x86/intel/uncore-freq: Display uncore current frequency.
Backport for intel-uncore-freqe driver

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Add a new sysfs attribute "current_freq_khz" to display current uncore
frequency. This value is read from MSR 0x621.

Root user permission is required to read uncore current frequency.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220204000306.2517447-4-srinivas.pandruvada@linux.intel.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: yingbao jia <yingbao.jia@intel.com>