asoc: set default value for port_id of logging kcontrol

Uninitialized values may cause the get function
of logging kcontrol to exit abnormally with error on
auto LA platform.

Change-Id: Id1f91a5454daafe499211763e26572bfe5dcbd47
Signed-off-by: Deru Wang <quic_deruwang@quicinc.com>