Support for Wireless USB and Ultra WideBand was removed in 2020 by
commit caa6772d ("Staging: remove wusbcore and UWB from the kernel
tree.").  But the documentation files were left behind.

Let's get rid of that out-of-date documentation.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/015d4310-bcd3-4ba4-9a0e-3664f281a9be@rowland.harvard.eduSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>