gen: update due to sdbusplus-gen-meson change

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I9491eb608d9c6849b3e39fe212054a3651bfb824
diff --git a/gen/xyz/openbmc_project/Common/Callout/meson.build b/gen/xyz/openbmc_project/Common/Callout/meson.build
index a8f8ce1..b89b52a 100644
--- a/gen/xyz/openbmc_project/Common/Callout/meson.build
+++ b/gen/xyz/openbmc_project/Common/Callout/meson.build
@@ -3,6 +3,7 @@
     'xyz/openbmc_project/Common/Callout__cpp'.underscorify(),
     input: [ '../../../../../yaml/xyz/openbmc_project/Common/Callout.errors.yaml',  ],
     output: [ 'error.cpp', 'error.hpp',  ],
+    depend_files: sdbusplusplus_depfiles,
     command: [
         sdbuspp_gen_meson_prog, '--command', 'cpp',
         '--output', meson.current_build_dir(),