Move minimal libc malloc to common library

[keith-packard]

This will (eventually) permit use of a common malloc implementation with
other C libraries, reducing the amount of Zephyr-specific code required
to support each C library.

This doesn't change the malloc implementation, it just moves the code and renames the
configuration variables.

Closes: #56243

[galak]

We should move all the Kconfig's in zephyr from MINIMAL_LIBC_MALLOC_* -> to COMMON_LIBC_MALLOC_*.

also document deprecation of the MINIMAL_LIBC_MALLOC_* Kconfigs in release notes

[keith-packard]

We should move all the Kconfig's in zephyr from MINIMAL_LIBC_MALLOC_* -> to COMMON_LIBC_MALLOC_*.

Thanks, I can do that.

also document deprecation of the MINIMAL_LIBC_MALLOC_* Kconfigs in release notes

Sounds good.

[keith-packard]

We should move all the Kconfig's in zephyr from MINIMAL_LIBC_MALLOC_* -> to COMMON_LIBC_MALLOC_*.

Done.

also document deprecation of the MINIMAL_LIBC_MALLOC_* Kconfigs in release notes

Not sure where these get added?

[keith-packard]

Lots of updates to clean up this series -- I've got another series stacked on top that switches picolibc -- https://github.com/keith-packard/zephyr/tree/picolibc-common-malloc -- but that required significant logic changes in how the heap is allocated to get alignment and 'use all memory' stuff working. I'll wait to submit that until this series is done, but if anyone is interested in where this is going, that should make it more clear.