RISC-V: Unify the output asm pattern between gpr_save and gpr_restore pattern.

RISC-V: Unify the output asm pattern between gpr_save and gpr_restore pattern.

gcc/ChangeLog:

	* config/riscv/riscv-protos.h (riscv_output_gpr_save): Remove.
	* config/riscv/riscv-sr.c (riscv_sr_match_prologue): Update
	value.
	* config/riscv/riscv.c (riscv_output_gpr_save): Remove.
	* config/riscv/riscv.md (gpr_save): Update output asm pattern.