target/loongarch: Move TCG specified functions to tcg_cpu.c

New file target/loongarch/tcg/tcg_cpu.c is created, and move TCG
specified functions to here from file target/loongarch/cpu.c

It is only code movement and there is no any function change.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250929035338.2320419-2-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
5 files changed