Hi okaner,
Can't you find the pflash demo from this link:
SDK_2.9.0_FRDM-KE04Z\boards\frdmke04z\driver_examples\flash\pflash
At lease, in the SDK 2.8.0, I still can find the pflash project, please check your SDK folder, whether you have that project or not?
If you still have issues about it, please kindly let me know.
Best Regards,
Kerry