tests/avocado: don't use tags to define drive

tests/avocado: don't use tags to define drive

We are abusing the avocado tags which are intended to provide test
selection metadata to provide parameters to our test. This works OK up
until the point you need to have ,'s in the field as this is the tag
separator character which is the case for a number of the drive
parameters. Fix this by making drive a parameter to the common helper
function.

Fixes: 267fe57c23 (tests: add tuxrun baseline test to avocado)
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230315174331.2959-11-alex.bennee@linaro.org>