gdbtypes.c: remove the usuned "top_level" parameter

gdbtypes.c: remove the usuned "top_level" parameter

This paramater is no longer useful after the previous commit, so remove
it as a cleanup.

gdb/ChangeLog:

	* gdbtypes.c (is_dynamic_type_internal): Remove the unused
	"top_level" parameter.
	(resolve_dynamic_type_internal): Remove the unused "top_level"
	parameter.  Update call to is_dynamic_type_internal.
	(is_dynamic_type): Update call to is_dynamic_type_internal.
	(resolve_dynamic_range): Update call to
	resolve_dynamic_type_internal.
	(resolve_dynamic_union): Likewise.
	(resolve_dynamic_struct): Likewise.
	(resolve_dynamic_type): Likewise.