m68k: replace cpu_m68k_init() with cpu_generic_init()

m68k: replace cpu_m68k_init() with cpu_generic_init()

call register_m68k_insns() at realize time which makes
cpu_m68k_init() typical object creation function.
As result we can replace it with cpu_generic_init()
which does the same job, reducing code duplication a bit.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Thomas Huth <huth@tuxfamily.org>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <1503592308-93913-12-git-send-email-imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>