OpenPicoRTOS v1.9.10

[jnaulet]

OpenPicoRTOS v1.9.10 is out !

What's new ?

This is a very minor update, we just fixed NXP's FlexCAN driver & added a new
Random Number Generator runtime API.

As static analysis evolves (especially cppcheck), what was acceptable isn't
anymore, so a lot of 'const' keywords had to be put everywhere to make things
more compliant.
Not everything can be fixed in that regard, as APIs might be used differently
in different drivers, leading to style warnings.

This release will be the last of the v1.9.x series, as the system will
(lightly) evolve in v1.10.x to add FIFO scheduling options.