ASoC: Fix slave port setup for lookahead bufferring

The slimbus slave port on the codec needs to be configured in order to
establish slimbus data path for look ahead bufferring. Fix existing
functionality to reuse generic slave port setup.

Change-Id: I095dd65437ec482278da4ad9cd812106bbeed9b3
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>