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_connector.h

@@ -1275,4 +1275,12 @@ int sde_connector_esd_status(struct drm_connector *connector);
 const char *sde_conn_get_topology_name(struct drm_connector *conn,
 		struct msm_display_topology topology);
 
+/*
+ * sde_connector_is_line_insertion_supported - get line insertion
+ * feature bit value from panel
+ * @sde_conn:    Pointer to sde connector structure
+ * @Return: line insertion support status
+ */
+bool sde_connector_is_line_insertion_supported(struct sde_connector *sde_conn);
+
 #endif /* _SDE_CONNECTOR_H_ */