ARM: S5PV210: fix unused LDO supply field from wm8994_pdata

According to commit 719a4240("mfd: Remove unused LDO supply field
from WM8994 pdata"), the LDO supply field should be removed from
the initializer.

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>