a2bus/4play.cpp: Fix player 4 joystick definition (#13084)

Fix an apparent copy-n-paste error.

Author: mgarlanger

src/devices/bus/a2bus/4play.cpp

@@ -70,14 +70,14 @@ static INPUT_PORTS_START( a24play )
 	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(3)
 
 	PORT_START("p4")
-	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_PLAYER(3)
-	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_PLAYER(3)
-	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_PLAYER(3)
-	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(3)
-	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_BUTTON3 ) PORT_PLAYER(3)
-	PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_UNKNOWN ) PORT_PLAYER(3)
-	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(3)
-	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(3)
+	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_PLAYER(4)
+	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_PLAYER(4)
+	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_PLAYER(4)
+	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_PLAYER(4)
+	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_BUTTON3 ) PORT_PLAYER(4)
+	PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_UNKNOWN ) PORT_PLAYER(4)
+	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(4)
+	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(4)
 INPUT_PORTS_END
 
 //-------------------------------------------------