hw/arm/virt: Check bypass iommu is not set for iommu-map DT property

hw/arm/virt: Check bypass iommu is not set for iommu-map DT property

default_bus_bypass_iommu tells us whether the bypass_iommu is set
for the default PCIe root bus. Make sure we check that before adding
the "iommu-map" DT property.

Cc: qemu-stable@nongnu.org
Fixes: 6d7a85483a06 ("hw/arm/virt: Add default_bus_bypass_iommu machine option")
Suggested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Donald Dutile <ddutile@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20250602114655.42920-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit f5ec751ee70d7960a97c6c675f69e924d82dc60d)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>