am3517_evm: add FIT support

Enable DTS support (CONFIG_OF_LIBFDT) and select
CONFIG_FIT in defconfig.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/am3517_evm.h b/include/configs/am3517_evm.h
index b90a60d..e9808a7 100644
--- a/include/configs/am3517_evm.h
+++ b/include/configs/am3517_evm.h
@@ -42,6 +42,8 @@
 
 #define CONFIG_MISC_INIT_R
 
+#define CONFIG_OF_LIBFDT
+
 #define CONFIG_CMDLINE_TAG		1	/* enable passing of ATAGs */
 #define CONFIG_SETUP_MEMORY_TAGS	1
 #define CONFIG_INITRD_TAG		1