staging: ozwpan: Remove from tree

Ozwpan is completely unmaintained and potentially a security problem. As
this is a staging driver, it should be removed, since it has been
abandoned.

Cc: Shigekatsu Tateno <shigekatsu.tateno@atmel.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>