ARM: S3C64XX: Update regulator names for debugfs compatiblity on SMDK6410

The debugfs support added to the regulator API (which has been merged
in during this merge window) creates directories for regulators named
after the display names for the regulators so replace / as a separator
for multiple supplies with + in the SMDK6410 machine.

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