Adding a pbs_config script is one way of making openmpi’s configure to succeed, but here also a simple manual way to do it:
export LD_LIBRARY_PATH=/opt/pbs/lib:$LD_LIBRARY_PATH
export LDFLAGS="-L/opt/pbs/lib -lpbs -lpthread -lcrypto"
./configure --with-tm=/opt/pbs
This should simply configure openmpi with PBS tm support. I tried with 2.0.2 as well.