Allow recovery to create device nodes and modify rootfs

tilapia's OTA code for updating the radio image needs to
create files on rootfs and create a character device in /dev.
Allow it.

Bug: 18281224
Change-Id: Ic408c2b28e16a40650f71efe2f17fb0c2e71f97f
grouper: power hal: improve interactive loads

-- ignore set_interactive(0) mode sets
-- decrease cpu load from 85% to 75% before ramping up; this way a core's
   frequency will be maxed out more aggressively
-- increase the hold time at max freq from 30ms to 500ms before beinning to
   ramp down; this way a core will stay longer at the maximum frequency, once
   there
-- increase timer sampling rate from 20ms to 50ms; this way cpufreq ramdown
   will be slower

Change-Id: I5d7e387f96db3601a2ab95fbac71359c7b3e81ba
Signed-off-by: Iliyan Malchev <malchev@google.com>
grouper: update prebuilt kernel and power hal

prebuilt kernel
	770b156 cpufreq: sysfs knobs for disabling hotplug during UI interaction

power hal:
	-- lock at least 2 cores for 3s when interactive
	-- when not interactive, revert to defaults.

Change-Id: I7b8993b801b9772c98a0e8ef210957f341f2f5c4
Signed-off-by: Iliyan Malchev <malchev@google.com>
grouper: emulate sdcard using 4 threads

This overrides the default of 2 threads.

Change-Id: Ie15b6a02499c5f9f25766c537d1b5a39d312a608
Signed-off-by: Iliyan Malchev <malchev@google.com>
grouper: update prebuilt kernel

6ff7a51 Revert "tegra3_android_defconfig: switch to SLUB"

b/18596108 GFXBench3 TRex test report unsupported on LRX22D

Change-Id: Icfecff7f5eef1d09cd56c846ea8ea0e4b7720c6d
Signed-off-by: Iliyan Malchev <malchev@google.com>
Merge branch 'cm-12.0' of github.com:CyanogenMod/android_device_asus_grouper into cm-12.0