hw/arm/aspeed_ast1700: Convert to DEFINE_TYPES() with inlined TypeInfo

Replace the legacy type_register_static()/type_init() registration
pattern with the modern DEFINE_TYPES() macro.

Inline the standalone TypeInfo variable directly into the
'aspeed_ast1700_types[]' array, removing the need for a separate
declaration.

No functional change.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20260601024959.2347639-12-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>