cpupower: Allow control of boost feature on non-x86 based systems with boost support.

The cpufreq subsystem has a generic sysfs interface for controlling boost
(/sys/devices/system/cpu/cpufreq/boost).
The sysfs interface can be used to enable boost control from the cpupower
command on non-x86 platforms as well. So, allow boost controlling
on non-x86 system if boost sysfs file exists.

The set subcommand enables/disables the boost feature using the following
syntax:
    cpupower set --boost 1
    cpupower set --boost 0

The --boost option is an alias for --turbo-boost. We provided the neutral
option name because the name "turbo boost" is specific to Intel technology.

The frequency-info subcommand displays the enabled/disabled state of
the boost feature as follows:
    boost state support:
        Active: yes (or no)

Link: https://lore.kernel.org/r/20250522061122.2149188-3-fj5851bi@fujitsu.com


Signed-off-by: Shinji Nomoto <fj5851bi@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>