Comments were not consistent, and this serves no purpose. There's no
reason to explicitly lock the flash first before unlocking. These bits
are simply set when the keys are written.
All the "f" type flash parts have an EOP flag, even if it's in different
bit positions. Add a header for this common functionality, and move
it's implementation to the existing common file.
Turns out, there's lots of common code for flash. Pull up prefetch
on/off to start with, as there's only a single bit name different.
Pull up the definitions of common API functions too, starting with
flash_set_ws. Even if the implementations are different, things that
meant to be the same, should be defined centrally.
