CPUFreq: Google's latest Interactive Governor

Signed-off-by: Locasto <amperific@gmail.com>
ondemandplus: implement io_is_busy

Based upon:
cpufreq: interactive: add io_is_busy interface
https://android.googlesource.com/kernel/common.git/+/fbcad7234e0aef2725d9f33ac5a0c3a9cc61a9ac

boype: adapted for 3.0 kernel
ondemandplus: tune for activated io_is_busy
fs/dcache.c: adaptive vfs_cache_pressure on suspend / resume

low vfs_cache pressure values save battery while idle, while
a low value also causes stutter with longer up times.
added 1.3 and 1.5 GHz CPU steps
omap2plus-cpufreq.c: only use maximum CPU overclock frequency if target frequency if above stock CPU maximum

If for example the highest CPU OPP (1.5 GHz) is enabled, all the below
frequencies are used as well, which increases the total number of
scaling steps and may hinder responsiveness. This patch only uses the
actual set maximum CPU frequency, if the requested frequency is above
the stock maximum frequency of 1.2 GHz.
fs/dache.c / mm/page-writeback.c: allow modification of dirty_-values and cache_pressure despite the dynamic suspend/resume values
Linux 3.0.84
opp4xxx.c: change 1305 MHz CPU step to 1344 MHz; tune voltages of CPU OC OPPs

1305 MHz is just a little too close to the stock 1228