hwmon: (adt7470) Replace power-of-two test

Since <linux/log2.h> already supplies a power-of-two test, there's no
point in having this source file redefine it again.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

drivers/hwmon/adt7470.c

@@ -114,8 +114,6 @@ I2C_CLIENT_INSMOD_1(adt7470);
 /* sleep 1s while gathering temperature data */
 #define TEMP_COLLECTION_TIME	1000
 
-#define power_of_2(x)	(((x) & ((x) - 1)) == 0)
-
 /* datasheet says to divide this number by the fan reading to get fan rpm */
 #define FAN_PERIOD_TO_RPM(x)	((90000 * 60) / (x))
 #define FAN_RPM_TO_PERIOD	FAN_PERIOD_TO_RPM
@@ -677,7 +675,7 @@ static int cvt_auto_temp(int input)
 {
 	if (input == ADT7470_PWM_ALL_TEMPS)
 		return 0;
-	if (input < 1 || !power_of_2(input))
+	if (input < 1 || !is_power_of_2(input))
 		return -EINVAL;
 	return ilog2(input) + 1;
 }