Looks like I can answer this one myself now.
It seems like NXP have released KSDK 2.0 without any announcement or fanfare on 28th Jan, the day I posted the above message.
I found this in the api document.
23.2.3 Input capture operations
The function FTM_SetupInputCapture()sets up an FTM channel for input capture. The
user can specify the capture edge and a filter value to be used when processing
the input signal.
The function FTM_SetupDualEdgeCapture()can be used to measure the pulse width of a
signal. A channel pair is used during capture with the input signal coming
through a channel n. The user can specify whether to use one-shot or continuous
capture, the capture edge for each channel, and any filter value to be used when
processing the input signal.
