Hi Mazen,
The units in the example of the Allan Deviation plots are seconds in the horizontal axis and rad/s for the vertical axis. This is because the input data provided to the allanvar command was in rad/s.
There is a few options to convert the vettical axes units to deg/h. You can either convert your input omega data to deg/h and then compute the Allan Deviation, or compute the Allan Deviation with your original data in deg/s and then convert to Allan Deviation values to deg/h.