disp: msm: expose qsync avr step as part of conn mode caps

Add capability to read avr step for each timing mode. This will
be in addition to the existing avr-step-list which is defined
when dfps is enabled. Expose the avr-step as part of each
mode in connector caps to user-mode.
Additionally, change the avr_step connector property to enum
to give usermode just the capability to enable/disable avr-step
and not alter the step value as its fixed from the device tree.

Change-Id: I6d7f8e9fcf03f98abef7640fc741e5e1be8597a1
Signed-off-by: Veera Sundaram Sankaran <quic_veeras@quicinc.com>

msm/sde/sde_kms.c

@@ -1829,7 +1829,7 @@ static int _sde_kms_setup_displays(struct drm_device *dev,
 		.set_allowed_mode_switch = dsi_conn_set_allowed_mode_switch,
 		.set_dyn_bit_clk = dsi_conn_set_dyn_bit_clk,
 		.get_qsync_min_fps = dsi_conn_get_qsync_min_fps,
-		.get_avr_step_req = dsi_display_get_avr_step_req_fps,
+		.get_avr_step_fps = dsi_conn_get_avr_step_fps,
 		.prepare_commit = dsi_conn_prepare_commit,
 		.set_submode_info = dsi_conn_set_submode_blob_info,
 		.get_num_lm_from_mode = dsi_conn_get_lm_from_mode,