XServiceInfo does not need to be declared as a supported sub-interface
for services, it is always implicitly there.
Also, for those services that now only contain one interface, convert
them to new-style service IDL declarations.

Change-Id: I325c27f287a02de6bdfc8bb6e5bf6c2a4ae0a753
Signed-off-by: Stephan Bergmann <sbergman@redhat.com>