mm: intel_adsp_mtl_tlb: suppress sparse address space warnings

There are various call to z_soc_cached_ptr() which returns values
in the cached address space and are stored in temporary variables
that are not marked as in the cached address space. This results
in sparse complaining about discarding the cached address space
attribute. These temporary variables are then passed to other
internal memory management related functions which do not have
the concept of cached address space (as it is currently Xtensa
specific). Because of this, we cannot change the signature of
these functions. Instead, we force a change of address space
when those temporary variables are being assigned to suppress
sparse warnings.

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