brcm63xx: fix CVG834G compatible string

The CVG834G claimed to be a BCM6348, but is actually BCM3368. Since we
don't test against it, this was harmless.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

target/linux/brcm63xx/dts/cvg834g.dts

@@ -6,7 +6,7 @@
 
 / {
 	model = "Netgear CVG834G";
-	compatible = "netgear,cvg834g", "brcm,bcm6348";
+	compatible = "netgear,cvg834g", "brcm,bcm3368";
 
 	chosen {
 		bootargs = "root=/dev/mtdblock2 rootfstype=squashfs,jffs2 noinitrd console=ttyS0,115200";