Add utility code to monitor host state

For SST (and possibly other PECI users), we need to know when CPU is not
available (to avoid using PECI), and when BIOS is booting (to avoid race
condition on configuring SST).

Subscribes to CurrentHostState to determine S5/S0 state, and also
CoreBiosDone to determine if BIOS is done.

Tested: as part of child change
Ie6eed8ab23bff289e01d6d125402a5509d3a9110

Signed-off-by: Jonathan Doman <jonathan.doman@intel.com>
Change-Id: I6a2ce21193d91a7efe53f7e48bcd57e685c903ff
3 files changed