drm/tests: helpers: Create the device in another function

We'll need in some tests to control when the device needs to be added
and removed, so let's split the device creation from the DRM device
creation function.

Reviewed-by: MaĆ­ra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-7-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
5 files changed