As mentioned in PCM/I2S Clock Setting in CYW20706 for Audio Applications - KBA228409, you can set I2S clock only to 44.1 kHz in master mode.
You can check following thread as well for configuration reference: Re: [CYBT-343026-01] A2DP I2S configuration (A2DP source, I2S slave) High clock rate
According to that thread that clock is supported in slave mode. So that should not be a problem. My problem here is that the data line is never pulling down as you can see in the picture I have attached.
This is solved. the PCM_OUT line was hooked up withthe UARt interface of the USB IC.
Thats great Ariel.!