sched: set scheduler multi-core power-savings to 2: this option tries to pack as much load as possible to cpu0 before using cpu1, as this is a dual-core device, this is exactly applicable to our device; from what i've seen, this does bring about some power savings, despite not actually hotplugging cpu1

Change-Id: I20e56d549783b37e70c23dae4ef1cf74741379c6
Signed-off-by: zwliew <zhaoweiliew@gmail.com>