mmc: sdhci-s3c: remove the sdhci-s3c-regs header file

Remove the sdhci-s3c-regs.h file.
Instead, it located those defined values into sdhci-s3c.c.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>