drm/dp: Fix documentation of DP tunnel functions

Fix the documentation issues below, also reported by 'make htmldocs':

drivers/gpu/drm/display/drm_dp_tunnel.c:447: warning: Function parameter or struct member 'tunnel' not described in 'drm_dp_tunnel_put'
drivers/gpu/drm/display/drm_dp_tunnel.c:447: warning: Function parameter or struct member 'tracker' not described in 'drm_dp_tunnel_put'
drivers/gpu/drm/display/drm_dp_tunnel.c:1185: warning: expecting prototype for drm_dp_tunnel_atomic_get_allocated_bw(). Prototype was for drm_dp_tunnel_get_allocated_bw() instead
drivers/gpu/drm/display/drm_dp_tunnel.c:1903: warning: Function parameter or struct member 'max_group_count' not described in 'drm_dp_tunnel_mgr_create'

Fixes: 295654f ("drm/dp: Add support for DP tunneling")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240228164636.1540903-1-imre.deak@intel.com

drivers/gpu/drm/display/drm_dp_tunnel.c

@@ -436,8 +436,8 @@ EXPORT_SYMBOL(drm_dp_tunnel_get);
 
 /**
  * drm_dp_tunnel_put - Put a reference for a DP tunnel
- * @tunnel - Tunnel object
- * @tracker - Debug tracker for the reference
+ * @tunnel: Tunnel object
+ * @tracker: Debug tracker for the reference
  *
  * Put a reference for @tunnel along with its debug *@tracker, which
  * was obtained with drm_dp_tunnel_get().
@@ -1170,7 +1170,7 @@ int drm_dp_tunnel_alloc_bw(struct drm_dp_tunnel *tunnel, int bw)
 EXPORT_SYMBOL(drm_dp_tunnel_alloc_bw);
 
 /**
- * drm_dp_tunnel_atomic_get_allocated_bw - Get the BW allocated for a DP tunnel
+ * drm_dp_tunnel_get_allocated_bw - Get the BW allocated for a DP tunnel
  * @tunnel: Tunnel object
  *
  * Get the current BW allocated for @tunnel. After the tunnel is created /
@@ -1892,6 +1892,7 @@ static void destroy_mgr(struct drm_dp_tunnel_mgr *mgr)
 /**
  * drm_dp_tunnel_mgr_create - Create a DP tunnel manager
  * @dev: DRM device object
+ * @max_group_count: Maximum number of tunnel groups
  *
  * Creates a DP tunnel manager for @dev.
  *