Fixing FreeBSD/arm in stable/9...

Just a quick note. I recently tried to create a FreeBSD-stable 9 image for an Atmel AT91SAM9G20 board I have. It didn't work. So, I tracked down the problems. It turns out that when the unmapped BIO changes went into stable/9 in revision r251874 a single revision (r246881) was missed. This left the ARM busdma API effectively non-functional. Unfortunately, this merge happened before the 9.2 release, so it is quite likely that all platforms of FreeBSD/arm didn't work in 9.2-RELEASE. I've not confirmed this, but the Atmel board I have wouldn't have working networking (and quite likely working USB) in 9.2-RELEASE. A few revisions later, the VM layout changed slightly. This also broke Atmel in a different way. I've corrected both of these issues and as of r259093, and I have my Atmel AT91SMA9G20 board working, at least mostly. There still appears to be an mbuf memory leak in the ate driver that takes the system out after a few hundred megabytes of traffic. This makes it less than completely useful in NFS root operations. My ultimate goal isn't an NFS root, but it is an network server, so I guess I better track the root cause of this down...