defconfig: enable standalone power collapse

Change-Id: I52a5c1e1655f53743a4ecbb1b41bef653236d460
Add SIO I/O scheduler

The Simple I/O scheduler is an extremely simple scheduler,
based on noop and deadline, that relies on deadlines to
ensure fairness. The algorithm does not do any sorting but
basic merging, trying to keep a minimum overhead. It is aimed
mainly for aleatory access devices (eg: flash devices).

Change-Id: I65cc09564ffae986d3c72146a0ea8040b8f117df