rootdir: Update cpufreq permissions when governor changes

 * Requires a kernel change to send the uevent.
 * This should alleviate some frustration that the performance/kernel
   folks have expressed regarding the Power HAL.

Change-Id: I31e6e13534159214a3b600082b7c0e4249433364
rootdir: Tighten permissions on boostpulse nodes

 * New PowerHAL code will only write to this as the system user, so
   remove the need for it to be world writable.

Change-Id: Ia9e69a6feff7c5ef1ff34a1180225e4008e8130f
rootdir: Set perms on interactive governor's min_sample_time

Change-Id: I75e9f424af731bdf1ca222eee2f4f18b20a6552b
rootdir: init.rc: set perms for cpufreq governor boostpulse_duration

Change-Id: I09b9a1ed548e4ffe1232f583e8ff5f026760f616