ar71xx: increase rb4xx nand kernel partition size (patch by danimo)

SVN-Revision: 23293

target/linux/ar71xx/files/drivers/mtd/nand/rb4xx_nand.c

@@ -60,7 +60,7 @@ static struct mtd_partition rb4xx_nand_partitions[] = {
 	{
 		.name	= "kernel",
 		.offset	= (256 * 1024),
-		.size	= (4 * 1024 * 1024) - (256 * 1024),
+		.size	= (6 * 1024 * 1024) - (256 * 1024),
 	},
 	{
 		.name	= "rootfs",