bcm968580xref: switch to CONFIG_OF_SEPARATE

The option OF_EMBED is deprecated,
so we switch to CONFIG_OF_SEPARATE

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
diff --git a/configs/bcm968580xref_ram_defconfig b/configs/bcm968580xref_ram_defconfig
index b23f960..1f433a3 100644
--- a/configs/bcm968580xref_ram_defconfig
+++ b/configs/bcm968580xref_ram_defconfig
@@ -18,7 +18,6 @@
 CONFIG_DOS_PARTITION=y
 CONFIG_ISO_PARTITION=y
 CONFIG_EFI_PARTITION=y
-CONFIG_OF_EMBED=y
 CONFIG_DEFAULT_DEVICE_TREE="bcm968580xref"
 # CONFIG_NET is not set
 CONFIG_BLK=y