[NDS32] Implment n9 pipeline.

[NDS32] Implment n9 pipeline.

gcc/
	* config.gcc (nds32*): Add nds32-utils.o into extra_objs.
	* config/nds32/nds32-n9-2r1w.md: New file.
	* config/nds32/nds32-n9-3r2w.md: New file.
	* config/nds32/nds32-opts.h (nds32_cpu_type, nds32_mul_type,
	nds32_register_ports): New or modify for cpu n9.
	* config/nds32/nds32-pipelines-auxiliary.c: Implementation for n9
	pipeline.
	* config/nds32/nds32-protos.h: More declarations for n9 pipeline.
	* config/nds32/nds32-utils.c: New file.
	* config/nds32/nds32.h (TARGET_PIPELINE_N9, TARGET_PIPELINE_SIMPLE,
	TARGET_MUL_SLOW): Define.
	* config/nds32/nds32.md (pipeline_model): New attribute.
	* config/nds32/nds32.opt (mcpu, mconfig-mul, mconfig-register-ports):
	New options that support cpu n9.
	* config/nds32/pipelines.md: Include n9 settings.
	* config/nds32/t-nds32 (nds32-utils.o): Add dependency.

Co-Authored-By: Chung-Ju Wu <jasonwucj@gmail.com>
From-SVN: r259218