via-ide: ensure that PCI_INTERRUPT_LINE is hard-wired to its default value

via-ide: ensure that PCI_INTERRUPT_LINE is hard-wired to its default value

Some firmwares accidentally write to PCI_INTERRUPT_LINE on startup which has
no effect on real hardware since it is hard-wired to its default value, but
causes the guest OS to become confused trying to initialise IDE devices
when running under QEMU.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-id: 20200313082444.2439-5-mark.cave-ayland@ilande.co.uk
Signed-off-by: John Snow <jsnow@redhat.com>