build: add vapi scripts to VPP_HOST_TOOLS_ONLY

vapi generators were missing from the VPP_HOST_TOOLS_ONLY, which
prevents building an out-of-tree plugin with API files. We now
install them.

Type: improvement
Signed-off-by: Guillaume Solignac <gsoligna@cisco.com>
Change-Id: Ie613c8f64034e933124325242f2f8b3ac3955878
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4ef4259..ee2882b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -220,6 +220,14 @@
 option(VPP_HOST_TOOLS_ONLY "Build only host tools" OFF)
 if(VPP_HOST_TOOLS_ONLY)
   set(SUBDIRS tools/vppapigen cmake)
+  install(
+    PROGRAMS
+    vpp-api/vapi/vapi_c_gen.py
+    vpp-api/vapi/vapi_cpp_gen.py
+    vpp-api/vapi/vapi_json_parser.py
+    DESTINATION ${VPP_RUNTIME_DIR}
+    COMPONENT vpp-dev
+  )
 elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
   find_package(OpenSSL)
   set(SUBDIRS