tests/acpi: Allow update of DSDT.cxl

tests/acpi: Allow update of DSDT.cxl

The _STA value returned currently indicates the ACPI0017 device
is not enabled.  Whilst this isn't a real device, setting _STA
like this may prevent an OS from enumerating it correctly and
hence from parsing the CEDT table.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240126120132.24248-11-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 14ec4ff3e4293635240ba5a7afe7a0f3ba447d31)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>