powerpc/dts: Correct sdhci quirk for bsc9131

We use property "sdhci,auto-cmd12" instead of "fsl,sdhci-auto-cmd12"
to distinguish if the sdhc host has quirk SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12.
Signed-off-by: NHaijun Zhang <Haijun.Zhang@freescale.com>
Signed-off-by: NScott Wood <scottwood@freescale.com>

arch/powerpc/boot/dts/fsl/bsc9131si-post.dtsi

@@ -130,7 +130,7 @@ usb@22000 {
 
 /include/ "pq3-esdhc-0.dtsi"
 	sdhc@2e000 {
-		fsl,sdhci-auto-cmd12;
+		sdhci,auto-cmd12;
 		interrupts = <41 0x2 0 0>;
 	};