USB fix using a FIQ to implement split transactions

This commit adds a FIQ implementaion that schedules
the split transactions using a FIQ so we don't get
held off by the interrupt latency of Linux
Merge branch 'rpi-3.9.y' of https://github.com/raspberrypi/linux into rpi-3.9.y+rmh-fbtft

* 'rpi-3.9.y' of https://github.com/raspberrypi/linux:
  USB fix using a FIQ to implement split transactions