Well, the TAS5805M is a decent amplifier for what you want to do. As can be read in its DS, "The device has an internal PLL that is used to take SCLK (Bit Clock) as reference clock and create the higher rate clocks required by the DSP and the DAC clock.", which is why an external MCLK is not needed. Same as with the PCM5102A and such.
As to the RPi, it's pretty common for SBCs that their I2S signals do not include MCLK, neither as an output or as an input.
The latter would require a hybrid master/slave mode, which is even less common on those SBCs. You can usually do this with MCUs supporting I2S, though. I have done this a few years ago with a dsPIC33 MCU, but there were pitfalls. If the external MCLK was not synchronized to the CPU clock, then you'd need to go through a code trick (software sync) in order for the I2S peripheral to start properly. That was bad. I dunno if the same pitfalls apply to other MCUs out there - but I'm suspecting so.