In short, SPS can be calculated by following formula: ADC frequency / (sampling bit + 4)
In detail, you can see SAR ADC component datasheet.
On CCGx SDKs, PDSS_PORT0_SAR_CLK is used as ADC clock that is 1MHz. (As per the CCGx Host/Power SDK User Guide, No changes are allowed.)
Thus, the result will be 83333 SPS = 1M/(8+4)