xr819-xradio: new package

This patch adds xradio wireless driver for SDIO WiFi chip XR819.
The out-of-tree driver is sourced from fifteenhex's work
on github https://github.com/fifteenhex/xradio

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
[Thomas: add entry in DEVELOPERS file.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
diff --git a/package/Config.in b/package/Config.in
index d2b3119..95068fd 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -505,6 +505,7 @@
 	source "package/wf111/Config.in"
 	source "package/wipe/Config.in"
 	source "package/xorriso/Config.in"
+	source "package/xr819-xradio/Config.in"
 endmenu
 
 menu "Interpreter languages and scripting"