tests: add rockchip to modetest, kmstest, vbltest and proptest

There is a rockchip drm kms driver.
Add "rockchip" to the static lists of driver names in the the standard
set of tests.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
[Emil Velikov: Resolve trivial conflicts.]
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>