( looking for a valid answer and not like please refer to the fan in of the respective IC)
The valid answer, as so often before, is "that depends".

What factors must be taken into account
a) You can, of course, not exceed the maximum Iol the datasheet specify per pin and for all pins
b) Are you current consumption sensitive, if so, you must use the highest value that will work
c) The pull-up must be low enough so that whatever is driven will get the required Vih.
d) Whith c) satisfied you may have to reduce further to achieve a faster risetime (pull-up vs stray capacitnce)

Erik

PS I'm sorry, twice above I referred to datasheet values and based on your request blew it.