ARM: shmobile: bockw: enable SMSC ethernet on defconfig

This patch adds SMSC ethernet support on Bock-W defconfig

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>