qsd8k: Make PowerHAL more flexible

 * Support boostpulse on both ondemand and interactive
 * Reopen the boostpulse node if it becomes invalid due to a governor
   change.

Kanged from: http://review.cyanogenmod.com/#/c/20919/

Change-Id: I0a95801686ec85ec779f42df18de32c767f3ad2b
Signed-off-by: Andrew Sutherland <dr3wsuth3rland@gmail.com>