ARM: EXYNOS: add initial setup-i2c0 for EXYNOS5

In all of Samsung platform, the setup-i2c0.c file for I2C channel 0
is always compiled. So when supporting new SoC,it should be updated
for it. Since EXYNOS5 GPIO will be supported after this, there is no
setup gpio in there now. It will be implemented with that, of course.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>