drm/amd/display/dc/bios_parser2: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c

@@ -265,6 +265,7 @@ static struct atom_display_object_path_v2 *get_bios_object(
 					&& id.enum_id == obj_id.enum_id)
 				return &bp->object_info_tbl.v1_4->display_path[i];
 		}
+		/* fall through */
 	case OBJECT_TYPE_CONNECTOR:
 	case OBJECT_TYPE_GENERIC:
 		/* Both Generic and Connector Object ID
@@ -277,6 +278,7 @@ static struct atom_display_object_path_v2 *get_bios_object(
 					&& id.enum_id == obj_id.enum_id)
 				return &bp->object_info_tbl.v1_4->display_path[i];
 		}
+		/* fall through */
 	default:
 		return NULL;
 	}