kernel: mem_domain: arch_mem_domain functions to return errors

This changes the arch_mem_domain_*() functions to return errors.
This allows the callers a chance to recover if needed.

Note that:
() For assertions where it can bail out early without side
   effects, these are converted to CHECKIF(). (Usually means
   that updating of page tables or translation tables has not
   been started yet.)
() Other assertions are retained to signal fatal errors during
   development.
() The additional CHECKIF() are structured so that it will bail
   early if possible. If errors are encountered inside a loop,
   it will still continue with the loop so it works as before
   this changes with assertions disabled.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>