target-cris: update CPU state save/load to use VMStateDescription

Update the CRIS CPU state save/load to use a VMStateDescription struct
rather than cpu_save/cpu_load functions.

Have to define TLBSet struct.
Multidimensional arrays in C are a mess, just unroll them.

Signed-off-by: Juan Quintela <quintela@redhat.com>
[PMM:
 * expand commit message a little since it's no longer one patch in
   a 35-patch series
 * add header/copyright comment to machine.c; credited copyright is
   Red Hat and author is Juan, since this commit gives the file all-new
   contents; license is LGPL-2-or-later, to match other target-cris code
 * remove hardcoded tab
 * add fields for locked_irq, interrupt_vector, fault_vector, trap_vector
 * drop minimum_version_id_old fields
 * bump version_id to 2 as we are not compatible with old state format
 * remove unnecessary hw/boards.h include
 * update to register via dc->vmsd]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>