[source] ramips: add build recipe for senao header

[LEDE Commits]

mkresin pushed a commit to source.git, branch master:
https://git.lede-project.org/483fd5f6ad7d87a8f24674c746c609e8b36b426f

commit 483fd5f6ad7d87a8f24674c746c609e8b36b426f
Author: Mathias Kresin <dev at kresin.me>
AuthorDate: Wed Aug 17 07:49:34 2016 +0200

    ramips: add build recipe for senao header
    
    Add it to the Makefile to allow a board which will be supported soon
    to use the recipe as well.
    
    Signed-off-by: Mathias Kresin <dev at kresin.me>
---
 target/linux/ramips/image/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/target/linux/ramips/image/Makefile b/target/linux/ramips/image/Makefile
index 7b53a2f..2af6d68 100644
--- a/target/linux/ramips/image/Makefile
+++ b/target/linux/ramips/image/Makefile
@@ -78,6 +78,11 @@ define Build/umedia-header
 	fix-u-media-header -T 0x46 -B $(1) -i $@ -o $@.new && mv $@.new $@
 endef
 
+define Build/senao-header
+	$(STAGING_DIR_HOST)/bin/mksenaofw $(1) -e $@ -o $@.new
+	mv $@.new $@
+endef
+
 #
 # The real magic happens inside these templates
 #