t6-common: set missing permission for scaling governor

Fixes following errors found in logcats

E/QCOM PowerHAL(  204): Error opening /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: Permission denied
E/QCOM PowerHAL(  204): Can't obtain scaling governor.

Change-Id: I57795d12dc5e077b83625cf848b7a14efbf3e64a