configs: lito: Replace loopback volume for tert mi2s with slimbus 8

Replace TERT MI2S LOOPBACK Volume with SLIMBUS_8 as
lito has cherokee which uses slimbus.

Change the pcm device id for offload usecase from 8 to 7.

Change the audio offload min duration from 60 to 30.

Change-Id: Ie4dc1a0c611d99876f4ecc12c0957ce89e5977b4
Signed-off-by: Vatsal Bucha <vbucha@codeaurora.org>