target-sparc: Convert to VMStateDescription

target-sparc: Convert to VMStateDescription

Convert the SPARC CPU from cpu_load/save functions to VMStateDescription.
We preserve migration compatibility with the previous version
(required for SPARC32 but not necessarily for SPARC64).

Signed-off-by: Juan Quintela <quintela@redhat.com>
[PMM:
 * Rebase and update to apply to master
 * VMSTATE_STRUCT_POINTER now takes type, not pointer-to-type
 * QEMUTimer* are migrated via VMSTATE_TIMER_PTR
 * Put CPUTimer vmstate struct inside TARGET_SPARC64 ifdef
 * Convert handling of PSR to use a vmstate_psr, like Alpha and ARM
]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>