cpufreq: interactive: calculate the load based on max (which is volatile) and not cpuinfo.max_freq, which is always 3GHz.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

idea is taken here - https://github.com/franciscofranco/mako/commit/cc519cfcfa70ab75a635309ac1d063fbd1f3e7e3