ARM: tegra: colibri: Replace eMMC label by comment

Rather than a bogus label just add a comment identifying the SDHCI
instance connected to the on-module eMMC.

Signed-off-by: Marcel Ziswiler <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>

arch/arm/boot/dts/tegra30-colibri.dtsi

···
 		nvidia,sys-clock-req-active-high;
 	};
 
-	emmc: sdhci@78000600 {
+	/* eMMC */
+	sdhci@78000600 {
 		status = "okay";
 		bus-width = <8>;
 		non-removable;