Support eMMC reset using DT for some exynos boards

This patchset is to support eMMC reset using DT for some exynos boards e.g. Odroid X2/U3/XU3.

It needs to reset eMMC memory to perform complete reboot, so we should handle nRESET_OUT line specially. nRESET_OUT line is connected to gpio and it can have different gpio by boards, so we will get gpio from DT.

This patchset is based on http://git.denx.de/u-boot-dm.git gpio-working branch.

Thanks.

Changes from v1:
- s/SD4_nRESET_OUT/nRESET_OUT
- Remove codes for non DT case
- Add comments about eMMC reset delay time

Joonyoung Shim (3):
samsung: board: support eMMC reset using DT
Odroid: Add eMMC-reset node on DT
Odroid-XU3: Add eMMC-reset node on DT

 arch/arm/dts/exynos4412-odroid.dts             |  5 +++++
 arch/arm/dts/exynos5422-odroidxu3.dts          |  5 +++++
 board/samsung/common/board.c                   | 28 ++++++++++++++++++++++++++++
 board/samsung/odroid/odroid.c                  |  8 --------
 doc/device-tree-bindings/exynos/emmc-reset.txt | 15 +++++++++++++++
 5 files changed, 53 insertions(+), 8 deletions(-)
 create mode 100644 doc/device-tree-bindings/exynos/emmc-reset.txt

applied to u-boot-samsung.

Thank,
Minkyu Kang.