Originally, normal dai link fixup callback is overwritten by sof fixup
callback on mtk_sof_card_late_probe and it relies on the mapping defined
on struct sof_conn_stream.

It's not flexible. When a new hardware connection is adopted, user needs
to update struct sof_conn_stream defined in machine driver which is used
to specify the mapping relationship of normal BE and SOF BE.

In the patch, mtk_sof_check_tplg_be_dai_link_fixup() is introduced for
all normal BEs. In mtk_sof_late_probe, back up normal BE fixup if it
exists and then overwrite be_hw_params_fixup by the new callback.

There are two cases for FE and BE connection.

case 1:
SOF FE -> normal BE
       -> SOF_BE

case 2:
normal FE -> normal BE

In the new fixup callback, it tries to find SOF_BE which connects to the
same FE, and then reuses the fixup of SOF_BE. If no SOF_BE exists,
it must be case 2, so rollback to the original fixup if it exists.

As a result, the predefined relation is not needed anymore. Hardware
connection can be controlled by the mixer control for AFE interconn.
Then, DPCM finds the BE mapping at runtime.
Signed-off-by: Trevor Wu <trevor.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230825024935.10878-3-trevor.wu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>