serrano: Set call recording source to voice line

Change-Id: Ie51be3225fd383a7ab8ca0d4862351d38601968d
serrano: Whitelist call recording for Nordic countries

 * Norway, Denmark, Sweden and Finland has a one-party consent law
   regarding private telephone recording. Meaning, any active
   participant in the call can initiate a recording without having
   to notify the other participant.

Change-Id: I48006ed0f4d9d8324b626af176d97dcf175a1f5d