Right now the information about which cases to use for what are in a
comment, but this is error prone.  Instead move all information into
a dedicated structure.

Tested-by: catalin@antebit.com
Reviewed-by: NPhilipp Zabel <philipp.zabel@gmail.com>
Tested-by: Philipp Zabel <philipp.zabel@gmail.com> # GA402RJ
Signed-off-by: NMario Limonciello <mario.limonciello@amd.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>