cpuidle: use BIT() for idle state flags and remove CPUIDLE_DRIVER_FLAGS_MASK

Use BIT() macro to do a small tidy-up.

CPUIDLE_DRIVER_FLAGS_MASK is not used, so remove it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/linux/cpuidle.h

@@ -69,11 +69,9 @@ struct cpuidle_state {
 
 /* Idle State Flags */
 #define CPUIDLE_FLAG_NONE       (0x00)
-#define CPUIDLE_FLAG_POLLING	(0x01) /* polling state */
-#define CPUIDLE_FLAG_COUPLED	(0x02) /* state applies to multiple cpus */
-#define CPUIDLE_FLAG_TIMER_STOP (0x04)  /* timer is stopped on this state */
-
-#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
+#define CPUIDLE_FLAG_POLLING	BIT(0) /* polling state */
+#define CPUIDLE_FLAG_COUPLED	BIT(1) /* state applies to multiple cpus */
+#define CPUIDLE_FLAG_TIMER_STOP BIT(2) /* timer is stopped on this state */
 
 struct cpuidle_device_kobj;
 struct cpuidle_state_kobj;