tests/functional: Convert the acpi-bits test into a standalone test

Mostly a straight-forward conversion. Looks like we can simply drop
the avocado datadrainer stuff when not using the avocado framework
anymore.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240830133841.142644-30-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 70dd243..f234464 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2074,8 +2074,8 @@
 M: Ani Sinha <anisinha@redhat.com>
 M: Michael S. Tsirkin <mst@redhat.com>
 S: Supported
-F: tests/avocado/acpi-bits/*
-F: tests/avocado/acpi-bits.py
+F: tests/functional/acpi-bits/*
+F: tests/functional/test_acpi_bits.py
 F: docs/devel/acpi-bits.rst
 
 ACPI/HEST/GHES