Introduce new signal S_NM_RUNNING_CHG and implement it for rcarrier,bbtransc

This allows different parts of the code to hook to some signals which
allow start/stopping processes based, for instance, on whether C0 is
available or not.
This can be later used by paging or CBSP code. Also ACC code can be
ported to this new system (acc_ramp_nm_sig_cb()).
Same signal can be used for other NM objects, but is left unimplemented
until there's use for them.

Change-Id: I206d4c7863a77fbab6a600126742a6a6b8fc3614
5 files changed