hal: Use Slimbus loopback volume for lito fm use case

Lito target uses Slimbus interface for FM use case.
Set Slimbus loopback volume instead of tertiary MI2S
to set the FM volume.

CRs-Fixed: 2461715
Change-Id: I92d40dfbec2738e40a1ad7fcaa259916b8b1290b
1 file changed