Define the Porter board dependent part of the R8A7791 sound device node.
Add device node for Asahi Kasei AK4642 stereo codec  to the I2C2 bus.
Add the "simple-audio-card" device node to interconnect the SoC sound
device  and the codec.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>