firmware: Allow hdmi_drive to override EDID
See: http://forum.stmlabs.com/showthread.php?tid=14050

firmware: qpu_execute: Don't write to V3D_VPMBASE: not required and khronos doesn't like it
See: http://www.raspberrypi.org/forums/viewtopic.php?f=68&t=76189

kernel: vchiq: Avoid high load when blocked and unkillable
See: https://github.com/raspberrypi/firmware/issues/271

userland: raspivid: Option to save the inline motion vectors to a file
See: https://github.com/raspberrypi/userland/pull/172