ARM: S3C6410: Use device names for both I2C clocks

When the S3C64xx CPUs were converted to clkdev mappings were added for the
I2C controllers on them. On S3C6410 a device name is specified for I2C
controller 1 but not for controller 0 which makes the code less robust as
we'll falsely return the clock for controller 0 if there's an error in the
request for controller 1.

Improve things by registering a device name for controller 0 as well. Due
to the fact that we change the numbering for controller 0 depending on if
we've registered controller 1 this requires an ifdef to choose the name.

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