Remove the old USB stack and related userland, etc. As detailed in UPDATING, users with a custom configuration file which was derived from a *GENERIC file before we made usb4bsd default (this happened in 3.6) might need to remove or comment out a couple of devices which are now unknown.
USB - Formalize polling mode and fix ohci interrupt storm * Formalize entering and leaving polling mode via usb_set_polling(). * Call bus->methods->do_poll() once when leaving polling mode to catch-up any lost interrupts. * OHCI now acknowledges interrupts from the interrupt handler when it finds itself in polling mode to prevent the interrupt from storming. The interrupts are recorded for later use.
USB - Fix polling code The polling code now calls the intr function instead of trying to optimize/shortcut the pending-interrupt test. There are additional conditions which need action which the test was not covering. The polling code now calls the softintr function as well, as it may be non-operational when the polling code is being used.
Nuke the code specific to NetBSD/OpenBSD/FreeBSD at first. I doubt anyone will update these pieces and I don't intend to review macros for all platforms. There is the chance though that I might kill something which should stay in the code in form "TODO: port it to DF". So, please review and kick me.