irda: move net/irda/ to drivers/staging/irda/net/

It's time to get rid of IRDA.  It's long been broken, and no one seems
to use it anymore.  So move it to staging and after a while, we can
delete it from there.

To start, move the network irda core from net/irda to
drivers/staging/irda/net/

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>