[RS6000] Fix PR20611, duplicate label for inlined function referencing TLS

[David Edelsohn]

	PR target/20611
	* config/rs6000/rs6000.md (load_toc_v4_PIC_1b): Remove inline
	label operand.  Remove (use (unspec..)).  Don't emit a label on
	the offset word.
	* config/rs6000/rs6000.c (rs6000_legitimize_tls_address): Don't
	generate inline label for load_toc_v4_PIC_1b.
	(rs6000_emit_load_toc_table): Likewise.

The unspec and the operand probably should have SImode, but otherwise it
looks okay.

Thanks, David