Set page to zero (for compatibility w/ devices supporting only first page).
Also init channel by default to -1 to disallow transfers for non-initialised
devices.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>

Add API to iterate over the wpan-phy instances.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>

Add a sysfs/in-kernel representation of LR-WPAN master devices.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>