add ondemandplus governor

Conflicts:
	include/linux/cpufreq.h
ondemandplus: add and enable io_is_busy=2 option, adjust up_threshold and down_differential
cpufreq: ondemandplus: add missing else if

There is no need to check for a frequency decrease if an
increase has already been initialized. Must have forgot
the 'else' a long time ago and never noticed it. Anyway,
it's only a slight code improvement.
cpufreq: ondemandplus: adaptive timer_rate improvements

1) reset last_cpu_freqs array when going idle
2) only use array when not idle, else use timer_rate * 3
defconfig: Update yuskey_hammerhead_defconfig

Enable SIOplus I/O Scheduler, Ondemandplus CPU Governor