hw/intc/aspeed: Introduce helper functions for enable and status registers

hw/intc/aspeed: Introduce helper functions for enable and status registers

The behavior of the enable and status registers is almost identical between
INTC(CPU Die) and INTCIO(IO Die). To reduce duplicated code, adds
"aspeed_intc_enable_handler" functions to handle enable register write
behavior and "aspeed_intc_status_handler" functions to handle status
register write behavior. 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/20250307035945.3698802-7-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>