drm/amd/display: Adjust functions documentation

Part of the documentation of the 'dc_process_dmub_aux_transfer_async'
function was misplaced, being put together with the
‘dc_enable_dmub_notifications’ documentation. This caused the following
warning:

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:3757: warning:
expecting prototype for dc_process_dmub_aux_transfer_async(). Prototype
was for dc_enable_dmub_notifications() instead

This commit fixes the warning by placing the function documentations in
their right place.
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NMagali Lemes <magalilemes00@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -3737,8 +3737,8 @@ bool dc_is_dmub_outbox_supported(struct dc *dc)
 	return dc->debug.enable_dmub_aux_for_legacy_ddc;
 }
 
-/**
- * dc_process_dmub_aux_transfer_async - Submits aux command to dmub via inbox message
+/*
+ *****************************************************************************
  *  Function: dc_enable_dmub_notifications
  *
  *  @brief
@@ -3780,7 +3780,7 @@ void dc_enable_dmub_outbox(struct dc *dc)
 }
 
 /**
- *****************************************************************************
+ * dc_process_dmub_aux_transfer_async - Submits aux command to dmub via inbox message
  *                                      Sets port index appropriately for legacy DDC
  * @dc: dc structure
  * @link_index: link index