Fix issue with Rfkill core and Nitrous BT power states out of sync.

Tidy up the initial states of both Rfkill and Nitrous to be blocked
(powered down) initially.  There was a mismatch in the states of
these two components that caused the rfkill_resume() to power the BT
back on erroneously when it should be stayed off.

Change-Id: I44ae0c58d697122475a5df77d5e015a6059000e0