Provide Linux-style IS_ERR()/PTR_ERR()/ERR_PTR() helpers

[jhedberg]

Linux has a very convenient feature of being able to encode POSIX error codes into pointers. This helps create simpler APIs where a pointer is returned but specific error information (beyond NULL return) is also required.

For reference:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/err.h

The above is a single implementation used for all architectures, but we may want to consider doing per-architecture header files in case Zephyr supports some architecture with special requirements.

[jhedberg]

Duplicate of #4973