ARM: tegra: colibri_t30: annotate sd card detect

Annotate SD card detect.
Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra30-colibri-eval-v3.dts

@@ -100,7 +100,7 @@ spidev0: spi@1 {
 	sdhci@78000200 {
 		status = "okay";
 		bus-width = <4>;
-		cd-gpios = <&gpio TEGRA_GPIO(C, 7) GPIO_ACTIVE_LOW>;
+		cd-gpios = <&gpio TEGRA_GPIO(C, 7) GPIO_ACTIVE_LOW>; /* MMCD */
 		no-1-8-v;
 	};