drm/msm: dpu: Handle crtc pm_runtime_resume() directly

Instead of registering through dpu_power_handle just to get a call on
runtime_resume, call the crtc function directly.

Changes in v2:
- None

Reviewed-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>

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