I found what I did earlier. It was a pain to track down, but I edited the CMakeCache.txt and added the LUA 5.1 paths manually. I'm sure there is a better way to do it, but I don't use cmake for my own projects and don't know my way around the files.
Code:
//Path to a file.
LUA_INCLUDE_DIR:PATH=/usr/include/lua-5.1
//Lua Libraries
LUA_LIBRARIES:STRING=/usr/lib64/liblua-5.1.so;/usr/lib64/libm.so
//Path to a library.
LUA_LIBRARY:FILEPATH=/usr/lib64/liblua-5.1.so