smbios-mdr: start 3 smbios instances to support single host machine The instance 3 is needed for single host machine. b/418691287#comment11 Fusion-Link: http://fusion2/a39cb216-5cba-3597-817b-be5910114501 Tested: https://paste.googleplex.com/4725589967372288 Platforms-Affected: platform15, platform24 Google-Bug-Id: 418691287 Change-Id: I1616e7c36326b068399fcc7f6cf2379104eecc32 Signed-off-by: Jinliang Wang <jinliangw@google.com> (cherry picked from commit 0de7fda35ce3eed5faf452201d39147a18b02f2c)