remove dead rotate code
remove dead rotate code

Never used, never defined. No opcode for rotate. Remove it.

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

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