msm/mdp5: Fix some kernel-doc warnings

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:227: warning: Function parameter or member 'ctl' not described in 'mdp5_ctl_set_encoder_state'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:227: warning: Function parameter or member 'pipeline' not described in 'mdp5_ctl_set_encoder_state'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:227: warning: Function parameter or member 'enabled' not described in 'mdp5_ctl_set_encoder_state'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:227: warning: Excess function parameter 'enable' description in 'mdp5_ctl_set_encoder_state'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:529: warning: Function parameter or member 'ctl' not described in 'mdp5_ctl_commit'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:529: warning: Function parameter or member 'pipeline' not described in 'mdp5_ctl_commit'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:529: warning: Function parameter or member 'flush_mask' not described in 'mdp5_ctl_commit'
 drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c:529: warning: Function parameter or member 'start' not described in 'mdp5_ctl_commit'

Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

drivers/gpu/drm/msm/disp/mdp5/mdp5_ctl.c

@@ -216,7 +216,9 @@ static void send_start_signal(struct mdp5_ctl *ctl)
 /**
  * mdp5_ctl_set_encoder_state() - set the encoder state
  *
- * @enable: true, when encoder is ready for data streaming; false, otherwise.
+ * @ctl:      the CTL instance
+ * @pipeline: the encoder's INTF + MIXER configuration
+ * @enabled:  true, when encoder is ready for data streaming; false, otherwise.
  *
  * Note:
  * This encoder state is needed to trigger START signal (data path kickoff).
@@ -510,6 +512,13 @@ static void fix_for_single_flush(struct mdp5_ctl *ctl, u32 *flush_mask,
 /**
  * mdp5_ctl_commit() - Register Flush
  *
+ * @ctl:        the CTL instance
+ * @pipeline:   the encoder's INTF + MIXER configuration
+ * @flush_mask: bitmask of display controller hw blocks to flush
+ * @start:      if true, immediately update flush registers and set START
+ *              bit, otherwise accumulate flush_mask bits until we are
+ *              ready to START
+ *
  * The flush register is used to indicate several registers are all
  * programmed, and are safe to update to the back copy of the double
  * buffered registers.