[DNM] manifest: add Xen module

Add the Xen include files as a module.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

Author: soburi

samples/hello_world/prj.conf

@@ -1 +1,2 @@
 # nothing here
+CONFIG_XEN_DOM0=y

samples/hello_world/src/main.c

@@ -6,6 +6,8 @@
 
 #include <stdio.h>
 
+#include <xen/public/xen.h>
+
 int main(void)
 {
 	printf("Hello World! %s\n", CONFIG_BOARD_TARGET);

west.yml

@@ -23,6 +23,8 @@ manifest:
       url-base: https://github.com/zephyrproject-rtos
     - name: babblesim
       url-base: https://github.com/BabbleSim
+    - name: soburi
+      url-base: https://github.com/soburi
 
   group-filter: [-babblesim, -optional]
 
@@ -367,6 +369,10 @@ manifest:
     - name: uoscore-uedhoc
       revision: 54abc109c9c0adfd53c70077744c14e454f04f4a
       path: modules/lib/uoscore-uedhoc
+    - name: xen
+      revision: b26dba6182bc2d7a14c2278af45cd243db308ad8
+      path: modules/lib/xen
+      remote: soburi
     - name: zcbor
       revision: 9b07780aca6fb21f82a241ba386ad9b379809337
       path: modules/lib/zcbor