yaml: move to subdirectory

A pending sdbusplus change (I38b69bc67b6a3d80cda1b508a76e106a50d8ab93)
is going to require YAML to be in a specific subdirectory and not in
the root.  Move here in prep for that change.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I42cd6599f751b34284243080dd213be3254d147c
diff --git a/gen/org/open_power/OCC/meson.build b/gen/org/open_power/OCC/meson.build
index 7433b15..c80db64 100644
--- a/gen/org/open_power/OCC/meson.build
+++ b/gen/org/open_power/OCC/meson.build
@@ -2,13 +2,14 @@
 subdir('Device')
 generated_others += custom_target(
     'org/open_power/OCC/Device__markdown'.underscorify(),
-    input: [ '../../../../org/open_power/OCC/Device.errors.yaml',  ],
+    input: [ '../../../../yaml/org/open_power/OCC/Device.errors.yaml',  ],
     output: [ 'Device.md' ],
+    depend_files: sdbusplusplus_depfiles,
     command: [
         sdbuspp_gen_meson_prog, '--command', 'markdown',
         '--output', meson.current_build_dir(),
         '--tool', sdbusplusplus_prog,
-        '--directory', meson.current_source_dir() / '../../../..',
+        '--directory', meson.current_source_dir() / '../../../../yaml',
         'org/open_power/OCC/Device',
     ],
 )