host/pine64: improve detection (#454)
host/pine64: improve detection (#454)

Read the model name from /proc/device-tree/model (via distro.DTModel())
instead of probing for /boot/pine64.dtb to be present.

There's various distros out there that don't have a /boot/pine64.dtb,
and /proc/device-tree/model is a much nicer way to do this.
google/periph