fix Support multiple input files in Makefile.service
fix Support multiple input files in Makefile.service

This commit fix Makefile.service to support multiple
input files which was introdce in this patch
I5ffbb4fdc0f4c44a14cd5066c0e80e5a8cd8fece

Change-Id: If8dd7eff983f917789e28aa23358b303718cfe58

opencord/xos,open-cloud/xos,open-cloud/xos,opencord/xos,opencord/xos,open-cloud/xos