ASoC: renesas: rz-ssi: Fix channel swap issue in full duplex mode

ASoC: renesas: rz-ssi: Fix channel swap issue in full duplex mode

The full duplex audio starts with half duplex mode and then switch to
full duplex mode (another FIFO reset) when both playback/capture
streams available leading to random audio left/right channel swap
issue. Fix this channel swap issue by detecting the full duplex
condition by populating struct dup variable in startup() callback
and synchronize starting both the play and capture at the same time
in rz_ssi_start().

Cc: stable@kernel.org
Fixes: 4f8cd05a4305 ("ASoC: sh: rz-ssi: Add full duplex support")
Co-developed-by: Tony Tang <tony.tang.ks@renesas.com>
Signed-off-by: Tony Tang <tony.tang.ks@renesas.com>
Reviewed-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://patch.msgid.link/20251114073709.4376-2-biju.das.jz@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>