ASoC: fsl_sai: Add separate DAI for transmitter and receiver

ASoC: fsl_sai: Add separate DAI for transmitter and receiver

The transmitter and receiver part of the SAI interface need to be
configured with different master/slave mode, especially to work
with the audiomix module.

+-------+               +-----------+
| SAI1  |   --TX-->     |           |
|       |   <--RX--     |           |
+-------+               |           |
                        | AUDIOMIX  |
+-------+               |           |
| SAI2  |   --TX-->     |           |
+-------+               +-----------+

The SAI1 TX is in master mode, but SAI1 RX is in slave mode.
So add another two DAIs for TX and RX separately. but only
defined fsl_sai_set_dai_fmt_tx() and fsl_sai_set_dai_fmt_rx()
ops function for current case, in the future, the other ops
function for TX and RX can be defined if required.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://patch.msgid.link/1718174452-17596-2-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>