tests: acpi: don't read all fields in test_acpi_fadt_table()

tests: acpi: don't read all fields in test_acpi_fadt_table()

there is no point to read fields here but not actually
checking them so drop it and read only header + dsdt/facs
addresses since it's needed later to fetch that tables.

With this cleanup we can get rid of AcpiFadtDescriptorRev3/
ACPI_FADT_COMMON_DEF which have no users left.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>