hammerhead: Set timer_rate for cpufreq governor

 * Reduces audio jitter

Change-Id: I0ee9c052ba07f0c5d5621cee868ce33fb68f7efc
Add keystore to system group

 * Required in order to request firmware for hardware implementation

Change-Id: Ibd1ba79667d4489f0972b8fba587a8ba9c6083dd
Update init binary