SC589 Maximum SPORT SCLK frequency

Table 29 page 81 of the ADSP-SC589 datasheet indicates that the maximum SPORT SCLK frequency (fSPRCLKEXT and fSPRCLKPROG)  is 31.25 MHz.

For 16 bit audio data at 48000KHz sampling rate this would restrict each SPORT to 64 channels which seems a bit low when the maximum number of channel supported is 1024. 

Also the restriction is given where fSPRCLKEXT <= fSCLK0 where fSCLK0 can be 125MHz.

Is it possible to externally clock the SPORT TX line at more than 31.25 MHz?