You mean, forever? Or for just when playing CSGO?
This one should disable it on both of the AMD/Intel aswell I think
echo 0 > /sys/devices/system/cpu/cpufreq/boost
Don’t forget to turn it back to 1 if you want to keep having turbo after you finished playing. Also it will not persist between reboots.
But better yet fix your cooling 
PCs should not overheat that easily.