im not an expert but it looks like make is getting confused by the two versions that you have installed (its using the header files from one version of png and the .c source files from another version).
try looking at the ./configure help to see if there is a switch you can use to say where the libpng files you want to use are.
should show you the different options that can be used and im assuming that the command you will want will look something like
just my thoughts anyway.
hope that helps some.