net/irda: Add SuperH IrDA driver support

This is very simple driver for SuperH Mobile IrDA
which support SIR/MIR/FIR.
This patch add only SIR support for now.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>