[ALSA] oxygen: remove magic numbers

Replace some magic numbers with register symbols.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/oxygen/oxygen_regs.h

@@ -360,10 +360,14 @@
 #define  OXYGEN_ADC_MONITOR_C_HALF_VOL	0x20
 
 #define OXYGEN_A_MONITOR_ROUTING	0xc4
-#define  OXYGEN_A_MONITOR_ROUTE_01_MASK	0x03
-#define  OXYGEN_A_MONITOR_ROUTE_23_MASK	0x0c
-#define  OXYGEN_A_MONITOR_ROUTE_45_MASK	0x30
-#define  OXYGEN_A_MONITOR_ROUTE_67_MASK	0xc0
+#define  OXYGEN_A_MONITOR_ROUTE_0_MASK	0x03
+#define  OXYGEN_A_MONITOR_ROUTE_0_SHIFT	0
+#define  OXYGEN_A_MONITOR_ROUTE_1_MASK	0x0c
+#define  OXYGEN_A_MONITOR_ROUTE_1_SHIFT	2
+#define  OXYGEN_A_MONITOR_ROUTE_2_MASK	0x30
+#define  OXYGEN_A_MONITOR_ROUTE_2_SHIFT	4
+#define  OXYGEN_A_MONITOR_ROUTE_3_MASK	0xc0
+#define  OXYGEN_A_MONITOR_ROUTE_3_SHIFT	6
 
 #define OXYGEN_AC97_CONTROL		0xd0
 #define  OXYGEN_AC97_COLD_RESET		0x0001