reset sweep at init

I was asked why SuperNSF square channels can't go low in most players (except VirtuaNSF). The problem is just that the sweep unit is muting them because they are never initialized.

Author: bbbradsmith

driver/source/main.asm

@@ -150,6 +150,10 @@ __init:
 	lda	#15
 	sta	$4015
 
+	lda	#$08
+	sta	$4001
+	sta	$4005
+	
 	lda	#3<<4
 	sta	$400C
 	lda	#31<<3
@@ -162,4 +166,4 @@ __init:
 __play:
 
 	jmp	pcm_mix_next
-	
+