target/loongarch: Use {set/get}_gpr replace to cpu_fpr

Introduce set_fpr() and get_fpr() and remove cpu_fpr.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20230504122810.4094787-44-gaosong@loongson.cn>
5 files changed