1.modify cmd_reg write error
2.add mmc debug info for exynos4412
3.modify exynos4412 sd det pin
	modified:   board/samsung/exynos4412/exynos4412.c
	modified:   common/cmd_reg.c
	modified:   drivers/mmc/mmc.c
	modified:   include/configs/exynos4412.h