ARM: shmobile: bockw: add dummy regulators for SMSC

SMSC driver will try to get regulator if .config had CONFIG_REGULATOR,
and, shmobile_defconfig has it.
SMSC driver on Bock-W board will be failed if it doens't have
dummy regulator settings.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>