Ordinal feature in decision tree
As per my knowledge, it doesn't matter for a decision tree model whether the features are ordinal or categorical. The goal is to create a model that predicts the value of a target variable by learning simple decision rules inferred from the data features. Decision trees describe patterns by using a list of attributes.

For a more detailed explanation, I am providing here some links which you will find helpful for such queries.
http://www.ibm.com/support/knowledgecenter/SS3RA7_17.0.0/clementine/nodes_treebuilding.html 

http://scikit-learn.org/stable/modules/tree.html

http://www.ryerson.ca/~rmichon/mkt700/SPSS/Creating%20Decision%20Trees.htm