ssi parameter is unused in rz_ssi_stream_init() so just drop it.

While at it, change the return type of rz_ssi_stream_init() to void
instead of int.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20220110094711.8574-4-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>