acpi-power-state-daemon: build: Subproject support

This makes it possible to build outside of the docker environment more
easily.

Change-Id: If33d68defee633c7116f2d9cdcdc8b164a8ec68f
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/subprojects/acpi-power-state-daemon/meson.build b/subprojects/acpi-power-state-daemon/meson.build
index acd34fd..691ae3f 100644
--- a/subprojects/acpi-power-state-daemon/meson.build
+++ b/subprojects/acpi-power-state-daemon/meson.build
@@ -31,7 +31,9 @@
 deps = [
   systemd,
   dependency('sdbusplus', fallback: ['sdbusplus', 'sdbusplus_dep']),
-  dependency('phosphor-dbus-interfaces'),
+  dependency(
+    'phosphor-dbus-interfaces',
+    fallback: ['phosphor-dbus-interfaces', 'phosphor_dbus_interfaces_dep']),
 ]
 
 bindir = get_option('prefix') / get_option('bindir')