freakz/driver: Clean the driver format

signed-off-by: Zhong Hongbo <bocui107@gmail.com>
freakz/driver: Delete the defind of the critical region

Delete AVR_ENTER_CRITICAL_REGION and AVR_LEAVE_CRITICAL_REGION.
Using cli to told the user the raw funciton in the critical
region.

signed-off-by: Zhong Hongbo <bocui107@gmail.com>
test_sim: Delet the pipe file in the fifo directory

In default, After simulator run, The pipe will reserve in the fifo.
When using grep tools to find some keywork. the pipe file will
loop in the fifo.

signed-off-by: Zhong Hongbo <bocui107@gmail.com>