disp: msm: sde: add line insertion support for sspp

Add line insertion support for sspp, this is used to support
display with external splitter. Line insertion logic checks
the difference between screen logical height and physical
height. If any difference is observed adds dummy and active
lines on screen.

Change-Id: Ieec322273df000a53fb39e05174c2d67c3c2da81
Signed-off-by: Rajesh kv <quic_kvrajesh@quicinc.com>

msm/sde/sde_encoder.h

@@ -683,5 +683,13 @@ static inline bool sde_encoder_is_widebus_enabled(struct drm_encoder *drm_enc)
 	return sde_enc->mode_info.wide_bus_en;
 }
 
+/*
+ * sde_encoder_is_line_insertion_supported - get line insertion
+ * feature bit value from panel
+ * @drm_enc:    Pointer to drm encoder structure
+ * @Return: line insertion support status
+ */
+bool sde_encoder_is_line_insertion_supported(struct drm_encoder *drm_enc);
+
 void sde_encoder_add_data_to_minidump_va(struct drm_encoder *drm_enc);
 #endif /* __SDE_ENCODER_H__ */