Interim cleanup with several small (but, as it turned out, fatal) bugs fixed. This commit mostly cleans the mouse code, but a second commit will finalize those changes.

src/machine/machine_ps2_mca.c

@@ -812,7 +812,7 @@ machine_ps2_common_init(machine_t *model)
         ps2_dma_init();
         keyboard_at_init();
         keyboard_at_init_ps2();
-        mouse_ps2_init();
+        mouse_ps2_init(NULL);
         nvr_at_init(8);
         pic2_init();