ARM: dts: exynos: Remove the cd-gpios property for eMMC of Odroid XU3/4

Odroid XU3/4 didn't need to use the cd-gpios for detecting card.
Because host controller has the CDETECT register through SDx_CDN line.
Host controller can know whether card is inserted or not with this
register.

When I have checked the Odroid XU3/4, they are using CDETECT register
(not using exteranl cd-gpio).

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>