imx6 : Change CPU frequency

ref: https://community.freescale.com/thread/317229

Hi, Carmili
     You can 

    "cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor" 
    
     to see what is the current governor you are using, 
     if it is interactive/conservative/ondemand, 
     then the cpu freq will be changed according to cpu's loading automatically. 

     If you want to change it manually, you need to switch it to userspace governor by 

     "echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"

     , then 

     "echo 792000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed" 

     is to set it to 792M, to 996M, using 996000. 
     
     To see current cpufreq, you can 

     "cat /sys/devices/system/cpu/cpu0/cpufreq/cur_cpufreq".