disp: msm: restrict AVR_STEP based on panel requirement

Some panels require a fixed step rate for a particular mode.
This change allows DSI panels to specify a single supported
step rate for each nominal fps rate which SDE will enforce
during atomic check of AVR parameters.

Change-Id: I049415449bc88ccd396fced16d4534251eac3a06
Signed-off-by: Steve Cohen <cohens@codeaurora.org>

msm/msm_drv.h

@@ -767,6 +767,7 @@ struct msm_resource_caps_info {
  * @roi_caps:           Region of interest capability info
  * @qsync_min_fps	Minimum fps supported by Qsync feature
  * @has_qsync_min_fps_list True if dsi-supported-qsync-min-fps-list exits
+ * @has_avr_step_req    Panel has defined requirement for AVR steps
  * @te_source		vsync source pin information
  * @dsc_count:		max dsc hw blocks used by display (only available
  *			for dsi display)
@@ -796,6 +797,7 @@ struct msm_display_info {
 
 	uint32_t qsync_min_fps;
 	bool has_qsync_min_fps_list;
+	bool has_avr_step_req;
 
 	uint32_t te_source;