sparc: move adhoc CPUSPARCState initialization to realize time

SPARCCPU::env was initialized from previously set properties
(with help of sparc_cpu_parse_features) in cpu_sparc_register().
However there is not reason to keep it there as this task is
typically done at realize time. So move post properties
initialization into sparc_cpu_realizefn, which brings
cpu_sparc_init() closer to cpu_generic_init().

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1503592308-93913-6-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
