ARM: ux500: Apply other compatible name to the u8540 DTS file

Devices in board DTS files are usually searchable by multiple
compatible strings. In this case the 8540 based SoC should be
obtainable via the chipset [DB8540 & AB8540] name 'u8540' or
the board name 'ccu8540'. It's already possible to obtain the
Device Tree via its chipset name, this patch makes it possible
to get it by its board name too.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/ccu8540.dts

@@ -14,7 +14,7 @@
 
 / {
 	model = "ST-Ericsson U8540 platform with Device Tree";
-	compatible = "st-ericsson,u8540";
+	compatible = "st-ericsson,ccu8540", "st-ericsson,u8540";
 
 	memory {
 		reg = <0x00000000 0x20000000>;