Fix QNX build - prioritize system EGL headers over the Khronos ones

configure.in

@@ -68,7 +68,7 @@ case "$host" in
 esac
 
 dnl Set up the compiler and linker flags
-INCLUDE="-I$srcdir/include -I$srcdir/src/video/khronos"
+INCLUDE="-I$srcdir/include -idirafter $srcdir/src/video/khronos"
 if test x$srcdir != x.; then
     INCLUDE="-Iinclude $INCLUDE"
 elif test -d .hg; then