Make smbus and addr as optional params in slot_data Per b/309873853, a new 4th cluster is needed with default bifurcation to 1x1. Testing: Added a new unit test to validate this case. Change-Id: Ieaf348b37b31473e67374a1eac9f5d064d5e4ead Signed-off-by: Vamsy Krishna Nooney <vamsykn@google.com>