ARM: SAMSUNG: change the name from s3c-sdhci to exynos4-sdhci

Thomas Arbrahams's patchset have changed the device name in sdhci-s3c.c
(mmc: sdhci-s3c: Rework platform data and add device tree support)
But didn't change the regulator_consumer name.
So maybe didn't initialize the mmc/sd card for exynos4.

This patch is fixed that (based-on linux-samsung for-next branch)

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>