* config/tc-arc.c (md_pseudo_table): Add .cpu.

	* config/tc-arc.c (md_pseudo_table): Add .cpu.
	(comment_chars): Add ';'.
	(arc_mach_type, mach_type_specified, cpu_tables_init_p): New globals.
	(md_parse_option): Delete support for -mmult.  Add -mcpu=xxx.
	(md_begin): Current ARCs are little endian.
	Call bfd_set_arch_mach to set the cpu type.
	(init_opcode_tables): New function.
	(md_begin): Ignore suffixes and registers not supported by cpu.
	(md_assemble): Initialize opcode tables here.
	Ignore opcodes not supported by selected cpu.
	Always ask for more memory in one piece.
	(arc_cpu): New function.
	(md_numbers_to_chars): Support both endians (will probably be needed
	eventually anyway).
	(md_apply_fix): Likewise.