disp: msm: sde: delay cwb done wait for last frame

Commit Ifa100424733 ("disp: msm: sde: delay
encoder disable for clone mode") delays the CWB
encoder disable but it is also skipping the CWB
disable flush. That can cause the underrun on dp
display if it uses the same 3d_merge HW block. This
change reverts the portion of original code and
only delays the last cwb frame done wait. It still
keep the last CWB frame done wait as it is if crtc
is also moving to inactive state.

Change-Id: I3461188a35197f2925899ceea7ef705adf00a398
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>

msm/sde/sde_encoder.h

@@ -495,6 +495,15 @@ void sde_encoder_recovery_events_handler(struct drm_encoder *encoder,
  */
 bool sde_encoder_in_clone_mode(struct drm_encoder *enc);
 
+/*
+ * sde_encoder_is_cwb_disabling - check if cwb encoder disable is pending
+ * @drm_enc:    Pointer to drm encoder structure
+ * @drm_crtc:    Pointer to drm crtc structure
+ * @Return: true if cwb encoder disable is pending
+ */
+bool sde_encoder_is_cwb_disabling(struct drm_encoder *drm_enc,
+	struct drm_crtc *drm_crtc);
+
 /**
  * sde_encoder_is_primary_display - checks if underlying display is primary
  *     display or not.