You need to think where you draw the line though. These are not NXP but ARM CMSIS files. I am 100% sure ARM is not going to change their policy on releasing their precious IP for non-restricted use. That is just not realistic.
As Brendon from NXP told me in his reply, the issue is with
chinese knock-off unspecified clone chip manufacturers, and it is not going to be easy to turn heads on this matter.
EDIT: the way ARM works is that they are not a chip manufacturer like Intel. They only develop IP (the core) and license it out to manufacturers (like NXP, Microchip, Apple) and so on. There is no way to license the CMSIS files in another way because that is what the manufacturers are de facto buying from ARM: a license to use the ARM IP.
EDIT: so, to put it bluntly, the only option is to allow a FOSS except the following: type clause