Port a wifi driver from kernel 4.19 to 5.4

Now using the PI4 we have seen known problems with 4.19.75 and need to port our wifi driver to work with 5.4.83. Our in house staff has estimated for a raspberry PI4 pro this is about 20 hours with debugging time.

Deliverables
Driver compatible with Kernel ver 5.4.83 Raspberry PI. We have a test setup to verify.