compilation: fix up for mismatched type for system_rev

Signed-off-by: Paul Reioux <reioux@gmail.com>
cpufreq: CPU max. hardlimit v1.1

SysFS interface:

* /sys/kernel/cpufreq/hardlimit (rw)
*
* set or show the real hard CPU frequency limit
*
* /sys/kernel/cpufreq/version (ro)
*
* display CPU freq hard limit version information