ARM: EXYNOS: Remove i2c sys configuration related code

As all these code has been moved into i2c driver, now we can
safely remove them from machine files.

CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>