ARM: dts: exynos: Remove double SD card detect pin inversion

The SDHCI standard, MMC host controller bindings and MMC core defines
card detect pin as active low.  Therefore there is no point to invert it
twice.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>