mac_via: use IFR bit flag constants for VIA2 IRQs

This allows us to easily see how the physical control lines are mapped to the
IFR bit flags.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220305150957.5053-4-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

include/hw/misc/mac_via.h

@@ -80,19 +80,18 @@ struct MOS6522Q800VIA1State {
 
 
 /* VIA 2 */
-#define VIA2_IRQ_SCSI_DATA_BIT  0
-#define VIA2_IRQ_NUBUS_BIT      1
-#define VIA2_IRQ_UNUSED_BIT     2
-#define VIA2_IRQ_SCSI_BIT       3
-#define VIA2_IRQ_ASC_BIT        4
+#define VIA2_IRQ_SCSI_DATA_BIT  CA2_INT_BIT
+#define VIA2_IRQ_NUBUS_BIT      CA1_INT_BIT
+#define VIA2_IRQ_SCSI_BIT       CB2_INT_BIT
+#define VIA2_IRQ_ASC_BIT        CB1_INT_BIT
 
 #define VIA2_IRQ_NB             8
 
-#define VIA2_IRQ_SCSI_DATA      (1 << VIA2_IRQ_SCSI_DATA_BIT)
-#define VIA2_IRQ_NUBUS          (1 << VIA2_IRQ_NUBUS_BIT)
-#define VIA2_IRQ_UNUSED         (1 << VIA2_IRQ_SCSI_BIT)
-#define VIA2_IRQ_SCSI           (1 << VIA2_IRQ_UNUSED_BIT)
-#define VIA2_IRQ_ASC            (1 << VIA2_IRQ_ASC_BIT)
+#define VIA2_IRQ_SCSI_DATA      BIT(VIA2_IRQ_SCSI_DATA_BIT)
+#define VIA2_IRQ_NUBUS          BIT(VIA2_IRQ_NUBUS_BIT)
+#define VIA2_IRQ_UNUSED         BIT(VIA2_IRQ_SCSI_BIT)
+#define VIA2_IRQ_SCSI           BIT(VIA2_IRQ_UNUSED_BIT)
+#define VIA2_IRQ_ASC            BIT(VIA2_IRQ_ASC_BIT)
 
 #define VIA2_NUBUS_IRQ_NB       7