arm: dts: exynos: Fix card-detect polarity for SD card on Odroid U3/X2

Card detect line for SD-card on Odroid U3/X2 boards are active low, so
add cd-inverted property to indicate this, as u-boot's GPIO driver doesn't
support specifying line polarity. This restores S5P_SDHCI driver operation
on Odroid U3/X2 boards.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>