boards: nxp: s32z2xxdc2: convert to hwmv2

Convert `s32z270dc2` boards to hardware model v2. The board has been
renamed to `s32z2xxdc2` to be able to support in the future other
SoCs from this series that can also work on this board.

Signed-off-by: Manuel Argüelles <manuel.arguelles@nxp.com>