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>
2 files changed