rtc: mv: use BIT()

Use bit instead of hand coding the shift and correct the 24 hour vs 24
hours typo.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c
index 4237622..7e84bb4 100644
--- a/drivers/rtc/rtc-mv.c
+++ b/drivers/rtc/rtc-mv.c
@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/rtc.h>
 #include <linux/bcd.h>
+#include <linux/bitops.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
@@ -24,7 +25,7 @@
 #define RTC_MINUTES_OFFS	8
 #define RTC_HOURS_OFFS		16
 #define RTC_WDAY_OFFS		24
-#define RTC_HOURS_12H_MODE		(1 << 22) /* 12 hours mode */
+#define RTC_HOURS_12H_MODE	BIT(22) /* 12 hour mode */
 
 #define RTC_DATE_REG_OFFS	4
 #define RTC_MDAY_OFFS		0
@@ -33,7 +34,7 @@
 
 #define RTC_ALARM_TIME_REG_OFFS	8
 #define RTC_ALARM_DATE_REG_OFFS	0xc
-#define RTC_ALARM_VALID		(1 << 7)
+#define RTC_ALARM_VALID		BIT(7)
 
 #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS	0x10
 #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS	0x14