m7: Fix BCM4335 chip crashes caused by BT/WiFI concurrency

 * The stock B+ driver works around chip crash that occurs when WiFi is
   on and BT is enabled/disabled by sending a magic patch to the
   hardware.
 * This patch was not in an external file, so some reverse engineering
   was required to extract it and put it in the correct format.
 * Enable the prepatch and enjoy crash-free Bluetooth :)

Change-Id: I1ec8ec345c459ce97cc389d270b025ef61363018