phosphor-dbus-interfaces: reduce package size

Enable LTO and ensure the generated markdown is not installed by adding
it to the 'doc' subpackage.

(From meta-phosphor rev: 6a07a16ffb83afe69f53ba4ace39aeed41e19965)

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Id012670431b2e4c9364cc74f6653b11214c19144
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/meta-phosphor/recipes-phosphor/dbus/phosphor-dbus-interfaces_git.bb b/meta-phosphor/recipes-phosphor/dbus/phosphor-dbus-interfaces_git.bb
index 0489097..98def67 100644
--- a/meta-phosphor/recipes-phosphor/dbus/phosphor-dbus-interfaces_git.bb
+++ b/meta-phosphor/recipes-phosphor/dbus/phosphor-dbus-interfaces_git.bb
@@ -29,4 +29,10 @@
         ])
 pdi_meson_config[vardeps] = "OBMC_ORG_YAML_SUBDIRS"
 
-EXTRA_OEMESON_append = " ${@pdi_meson_config(d)}"
+# Markdown files are installed into /usr/share/phosphor-dbus-interfaces so
+# add them to the 'doc' subpackage.
+FILES_${PN}-doc += "${datadir}/${BPN}"
+
+EXTRA_OEMESON_append = " \
+        -Db_lto=true \
+        ${@pdi_meson_config(d)}"