drm/msm/adreno: slight init order cleanup

Move anything that can fail after call to base class msm_gpu_init().
This way, if we fail, active_list has already been initialized so we
don't trip 'WARN_ON(!list_empty(&gpu->active_list))' in
msm_gpu_cleanup().

Signed-off-by: Rob Clark <robdclark@gmail.com>