Reverted rev 339. Fixes Adlib Gold jukebox.

Disable PIT timer operation between write of control word and initial count. Lemmings High Performance PC mode now works without incorrect rev 339 commit.

src/ibm.h

@@ -214,6 +214,7 @@ typedef struct PIT
         int using_timer[3];
         int initial[3];
         int latched[3];
+        int disabled[3];
 } PIT;
 
 PIT pit;