tests/acpi/bios-tables-test: use the correct slot on the pcie-root-port

tests/acpi/bios-tables-test: use the correct slot on the pcie-root-port

PCIE ports only have one slot, slot 0. Hence, non-zero slots are not available
for PCIE devices on PCIE root ports. Fix test_acpi_q35_tcg_no_acpi_hotplug()
so that the test does not use them.

Signed-off-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20230705115925.5339-3-anisinha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>