block: add simple 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).

Signed-off-by: Humberto Borba <humberos@gmail.com>
config: add simple i/o as default scheduler

Signed-off-by: Humberto Borba <humberos@gmail.com>
drivers: cpufreq: add interactive cpu governor

This driver adds a dynamic cpufreq policy governor.
Designed for low latency burst workloads.
Scaling it done when coming out of idle instead of polling.

Also, this gets full cpu frequency scaling for workloads
that are latency sensitive, typically interactive workloads.

Signed-off-by: Humberto Borba <humberos@gmail.com>
config: add interactive cpu governor

Signed-off-by: Humberto Borba <humberos@gmail.com>
drivers: add backoff support

Holds a wakelock if you suspend too often.

Signed-off-by: Humberto Borba <humberos@gmail.com>
config: add backoff driver support

Signed-off-by: Humberto Borba <humberos@gmail.com>