disp: msm: sde: fix dsc initial line caluclation

Current DSC intial line calculation is giving extra line on top of
recommended value from systems since number of active soft slices
considered is wrong. Fix the number or usage of active soft slices
in an encoder to align dsc initial line with recommended setting.

Change-Id: I321260e22b7824b8c481a55b54831ce9535661cc
Signed-off-by: Prabhanjan Kandula <pkandula@codeaurora.org>

msm/msm_drv.h

@@ -409,6 +409,7 @@ struct msm_roi_caps {
  * @pclk_per_line:           Compressed width.
  * @slice_last_group_size:   Size of last group in pixels.
  * @slice_per_pkt:           Number of slices per packet.
+ * @num_active_ss_per_enc:   Number of active soft slices per encoder.
  * @source_color_space:      Source color space of DSC encoder
  * @chroma_format:           Chroma_format of DSC encoder.
  * @det_thresh_flatness:     Flatness threshold.
@@ -433,6 +434,7 @@ struct msm_display_dsc_info {
 	int pclk_per_line;
 	int slice_last_group_size;
 	int slice_per_pkt;
+	int num_active_ss_per_enc;
 	int source_color_space;
 	int chroma_format;
 	int det_thresh_flatness;