Properly create and use a bfd_arch_info_type for 32-bit tilegx.

Properly create and use a bfd_arch_info_type for 32-bit tilegx.

bfd/
	* arctures.c (bfd_architecture): Define bfd_mach_tilegx32.
	* bfd-in2.h: Regenerate.
	* cpu-tilegx.c (bfd_tilegx32_arch): define.
	  (bfd_tilegx_arch): link to bfd_tilegx32_arch.

gas/
	* tc-tilegx.c (md_begin): set architecture and machine.