Remove: libtimidity support (NOT timidity support)

libtimidity was introduced with the support for PSP. PSP has been
dropped almost a year ago, but this music driver was not. This
corrects that oversight.

timidity (via extmidi) still works fine. This purely removes the
libtimidity support, which was only really available for PSP.

projects/generate

@@ -138,7 +138,6 @@ load_main_data() {
 			if ($0 == "MSVC"        && "'$os'" != "MSVC")              { next; }
 			if ($0 == "DIRECTMUSIC" && "'$enable_directmusic'" != "1") { next; }
 			if ($0 == "FLUIDSYNTH"  && "'$enable_fluidsynth'" != "1")  { next; }
-			if ($0 == "LIBTIMIDITY" && "'$libtimidity'" == "" )        { next; }
 			if ($0 == "HAVE_THREAD" && "'$with_threads'" == "0")       { next; }
 
 			skip += 1;