ARM: dts: exynos: Add pin configuration for SD write protect on Odroid XU3/XU4/HC1

Add SD card write-protect pin configuration to be sure that it will be
properly pulled down to indicate write access.

Suggested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>