as of rev 1.16 of bktr_core.c, bktr(4) enables the audio muxes at attach, and doesn't disable them ever.
as of rev 1.16 of bktr_core.c, bktr(4) enables the audio muxes at
attach, and doesn't disable them ever.

this removes the enabling/disabling of the audio muxes in the radio(4)
interface for bktr(4) as well.

OK robert@, mickey@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars