I'm looking into adding an external clock as a master clock input on one of the SAI's (for example SAI2) in the IMX8M plus.
The reference manual on chapter 14.1.1.1 states
"The MCLK pin on each SAI module can be configured as either an input or an output. [...] When configured as an input, the external input to the pad will be used as SAIn_MCLK and is routed to SAIn_MCLK_IN, which can be used as master clock for SAI."
However, there don't seem to be any registers in the GPR's that set the SAIn_MCLK as input, in contrast to the IMX8M mini and IMX8M nano.
Below are screenshots of the GPR2 in the IMX8M nano and plus.
IMX8M nano GPR2 (has ext_mclk_en)

IMX8M plus GPR2

Does this mean it is not supported? Am I missing something?
Thanks in advance, any help would be much appreciated.