target/mips: Avoid qemu_semihosting_log_out for UHI_plog

target/mips: Avoid qemu_semihosting_log_out for UHI_plog

Use semihost_sys_write and/or qemu_semihosting_console_write
for implementing plog.  When using gdbstub, copy the temp
string below the stack so that gdb has a guest address from
which to perform the log.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220628111701.677216-5-richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>