Real-time Raspbian image update for Navio

[igor.vereninov]

@mb300sd Discussion on RPi2 kernel is here:

Raspberry 2 realtime kernel image

Well, it’s 99% ready, there is only one thing holding us - unstable work of rt kernel with usb driver on RPi2. The problem is that new RPi’s USB driver uses FIQ and it somehow causes hangs on SMP system under rt preempt, while the standard USB driver doesn’t work on Raspberry Pi 2 at all. I’ve contacted Raspberry Pi Foundation and opened an issue about the standard USB driver, hope we can work something out soon.

It is hard to estimate when it will be ready.