bpp3: add bpp3 board
bpp3: add bpp3 config
- add ulpi
- add ramdisk
- add dynamic frequency
- ramdisk must be linked not a module
- add ipv6 and nfs 4.1 support
- add legacy ptys to fix the following error "Starting Bootlog
  daemon: bootlogd: cannot allocate pseudo tty: No such file or directory"