test: Call test_pre/post_run() from driver model tests

test: Call test_pre/post_run() from driver model tests

Ultimately we want to get rid of the special driver model test init and
use test_pre_run() and test_post_run() for all tests. As a first step,
use those function to handle console recording.

For now we need a special case for setting uts->start, but that wil go
away once all init is in one place.

Signed-off-by: Simon Glass <sjg@chromium.org>