hw/ide/pci: Add PCIIDEState::isa_irq[]

hw/ide/pci: Add PCIIDEState::isa_irq[]

These legacy ISA IRQs allow the PIIX IDE functions to be wired up in
their south bridges and the VIA IDE functions to disuse
PCI_INTERRUPT_LINE as outlined in https://lists.nongnu.org/archive/html/qemu-devel/2020-03/msg01707.html

Suggested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230126211740.66874-7-shentey@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>