sched: set sched_smt_power_savings to 2

The smt in the name of the sched_smt_power_savings parameter represents simultaneous multithreading. This scheduler power saving feature corresponds to the /sys/devices/system/cpu/sched_smt_power_savings file. The default value of this parameter is 0, which does nothing When it is set to 1, the scheduler tries to schedule processes on the least number of hyper-threads on a core as possible. In other words, the process load is distributed such that all the hyper-threads in a core and all the cores within the same processor are busy before the load is distributed to other hyper-threads and cores in another processor. As with the sched_mc_power_savings parameter, power is saved by reducing the number of active hyper-threads while allowing the idle processors to go into a deeper C-state.