target/loongarch: Set function loongarch_map_address() with common code

target/loongarch: Set function loongarch_map_address() with common code

Function loongarch_map_address is to get physical address from virtual
address, it is used by qmp commands to dump memory from virtual
address.

It is used by kvm mode also, here move function loongarch_map_address()
out of macro CONFIG_TCG. And it is common code, the similar with
function loongarch_page_table_walker().

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250423080417.3739809-6-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>