make wcsr, bret and eret privileged
make wcsr, bret and eret privileged

Make wcsr, bret and eret NOOPs if the processor is not in kernel mode.

Signed-off-by: Michael Walle <17b9e1c64588c7fa6419b4d29dc1f4426279ba01@walle.cc>

litex-hub/pythondata-cpu-lm32,litex-hub/pythondata-cpu-lm32