ARM: pxa: dts: fix mmc controller compatible string

The vendor prefix was renamed from "mrvl" to "marvell". Follow this
change in the dts file.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

arch/arm/boot/dts/pxa2xx.dtsi

@@ -120,7 +120,7 @@ usb0: ohci@4c000000 {
 		};
 
 		mmc0: mmc@41100000 {
-			compatible = "mrvl,pxa-mmc";
+			compatible = "marvell,pxa-mmc";
 			reg = <0x41100000 0x1000>;
 			interrupts = <23>;
 			status = "disabled";