Yes! You will create a custom scale (click "Grades" to "Choose an Action" and pick "Edit" "Scales". You "add a new scale". Name is something like P/F. For the "Standard scale" type in Pass,Fail
Remember that typing counts as they will see what you put in as the standard scale. Click "Save changes". You can only edit this scale if you have not used it or remove it as the scale of choice for items. Now when you create your assignment you can select the scale from the top of the list. Marvy!