radio: iris: Maintain different FM states

Unexpected disabled event gets queued when FM is turned
on after turning off FM, sending SSR command. Therefore
FM fails to turn on.Maintain different states FM OFF,
FM RECV TURNING ON, FM TRANS TURNING ON, FM_OFF,
FM CALIBRATION and only queue unexpected disabled event
when either Receiver or Transmitter is enabled.

CRs-Fixed: 518378

Change-Id: Iffa55bef3dc5ce605cf270ad41f4c9a8b8d70392
Signed-off-by: Ayaz Ahmad <aahmad@codeaurora.org>