iio: accel: adxl345: use HZ macro from units.h

Remove duplicated definition of NHZ_PER_HZ, because it's available in
the units.h as NANOHZ_PER_HZ.
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220812165243.22177-4-ddrokosov@sberdevices.ruSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/adxl345_core.c

@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
+#include <linux/units.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -32,7 +33,6 @@
 
 #define ADXL345_BW_RATE			GENMASK(3, 0)
 #define ADXL345_BASE_RATE_NANO_HZ	97656250LL
-#define NHZ_PER_HZ			1000000000LL
 
 #define ADXL345_POWER_CTL_MEASURE	BIT(3)
 #define ADXL345_POWER_CTL_STANDBY	0x00
@@ -139,7 +139,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 
 		samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ <<
 				(regval & ADXL345_BW_RATE);
-		*val = div_s64_rem(samp_freq_nhz, NHZ_PER_HZ, val2);
+		*val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2);
 
 		return IIO_VAL_INT_PLUS_NANO;
 	}
@@ -164,7 +164,8 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
 				    ADXL345_REG_OFS_AXIS(chan->address),
 				    val / 4);
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		n = div_s64(val * NHZ_PER_HZ + val2, ADXL345_BASE_RATE_NANO_HZ);
+		n = div_s64(val * NANOHZ_PER_HZ + val2,
+			    ADXL345_BASE_RATE_NANO_HZ);
 
 		return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE,
 					  ADXL345_BW_RATE,