MIPS: ath79: Add basic device tree support

Add the bare minimum to load a device tree.

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 733f6ac..164d8c73 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -134,6 +134,7 @@
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_MIPS16
 	select SYS_SUPPORTS_ZBOOT
+	select USE_OF
 	help
 	  Support for the Atheros AR71XX/AR724X/AR913X SoCs.