mmc: clarify DDR timing mode between SD-UHS and eMMC

This change distinguishes DDR timing mode of current
mixed usage to clarify device type.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

diff --cc drivers/mmc/core/debugfs.c
Simple merge

diff --cc drivers/mmc/core/mmc.c
Simple merge

diff --cc include/linux/mmc/host.h
Simple merge