disp: msm: sde: calculate line_time once during modeset

Calculate line_time once during modeset and allow
each plane to use it instead of calculating for each frame.
It also simplifies the line_time calculation for
command mode display.

Change-Id: I94ce29eec94bfdbee9016fbf93378661ebf79c03
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>

msm/sde/sde_encoder_phys.h

@@ -542,14 +542,6 @@ void sde_encoder_phys_setup_cdm(struct sde_encoder_phys *phys_enc,
 void sde_encoder_helper_get_pp_line_count(struct drm_encoder *drm_enc,
 		struct sde_hw_pp_vsync_info *info);
 
-/**
- * sde_encoder_helper_get_transfer_time - get the mdp transfer time in usecs
- * @drm_enc: Pointer to drm encoder structure
- * @transfer_time_us: Pointer to store the output value
- */
-void sde_encoder_helper_get_transfer_time(struct drm_encoder *drm_enc,
-		u32 *transfer_time_us);
-
 /**
  * sde_encoder_helper_trigger_flush - control flush helper function
  *	This helper function may be optionally specified by physical