tests/qtest/bios-tables-test.c: Add support for arch in path

tests/qtest/bios-tables-test.c: Add support for arch in path

Since machine name can be common for multiple architectures (ex: virt),
add "arch" in the path to search for expected AML files. Since the AML
files are still under old path, add support for searching with and
without arch in the path.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20240625150839.1358279-7-sunilvl@ventanamicro.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>