uwb: Remove the WLP subsystem and drivers

The only Wimedia LLC Protocol (WLP) hardware was an Intel i1480 chip
with a beta release of firmware that was never commercially available as
a product.  This hardware and firmware is no longer available as Intel
sold their UWB/WLP IP.  I also see little prospect of other WLP
capable hardware ever being available.

Signed-off-by: David Vrabel <david.vrabel@csr.com>