Probably a udev rule would do the trick:
KERNEL=="DspBridge", MODE="0666"
This is what I see on my N9:
crw-rw-rw- 1 root root 251, 0 Feb 13 21:52 /dev/DspBridge
Of course, you can manually chmod as root to whatever you want I guess.
Cheers.
--
Felipe Contreras