block: 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).

Conflicts:
	block/Kconfig.iosched

Change-Id: I8fd1a2b2112a848fd232a86469885de832f6a6b9
block: sio-ioched: some tweaks from AK.

Conflicts:
	block/sio-iosched.c

Change-Id: I2efad841e6a77c4739400ebe084f3fcaec685896