iio: imu: mpu6050: fix INV_MPU6050_REG_UP_TIME delay

replace msleep(INV_MPU6050_REG_UP_TIME) with usleep_range calls
due to fact the wait time is under 20 milliseconds.
Signed-off-by: Matt Ranostay <matt.ranostay@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -151,7 +151,8 @@ int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on)
 		return result;
 
 	if (power_on)
-		msleep(INV_MPU6050_REG_UP_TIME);
+		usleep_range(INV_MPU6050_REG_UP_TIME_MIN,
+			     INV_MPU6050_REG_UP_TIME_MAX);
 
 	return 0;
 }

drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

@@ -68,7 +68,8 @@ static int inv_mpu6050_select_bypass(struct i2c_adapter *adap, void *mux_priv,
 		if (ret)
 			goto write_error;
 
-		msleep(INV_MPU6050_REG_UP_TIME);
+		usleep_range(INV_MPU6050_REG_UP_TIME_MIN,
+			     INV_MPU6050_REG_UP_TIME_MAX);
 	}
 	if (!ret) {
 		st->powerup_count++;

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

@@ -172,10 +172,15 @@ struct inv_mpu6050_state {
 #define INV_MPU6050_BYTES_PER_3AXIS_SENSOR   6
 #define INV_MPU6050_FIFO_COUNT_BYTE          2
 #define INV_MPU6050_FIFO_THRESHOLD           500
+
+/* delay time in milliseconds */
 #define INV_MPU6050_POWER_UP_TIME            100
 #define INV_MPU6050_TEMP_UP_TIME             100
 #define INV_MPU6050_SENSOR_UP_TIME           30
-#define INV_MPU6050_REG_UP_TIME              5
+
+/* delay time in microseconds */
+#define INV_MPU6050_REG_UP_TIME_MIN          5000
+#define INV_MPU6050_REG_UP_TIME_MAX          10000
 
 #define INV_MPU6050_TEMP_OFFSET	             12421
 #define INV_MPU6050_TEMP_SCALE               2941