iio: imu: inv_mpu6050: make arrays hz and d static

Don't populate the arrays on the stack, instead make them static.
Makes the object code smaller by 135 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
  15135	   4240	    128	  19503	   4c2f	inv_mpu_core.o

After:
   text	   data	    bss	    dec	    hex	filename
  14840	   4400	    128	  19368	   4ba8	inv_mpu_core.o

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/inv_mpu6050/inv_mpu_core.c

@@ -572,10 +572,12 @@ error_write_raw_unlock:
  */
 static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
 {
-	const int hz[] = {188, 98, 42, 20, 10, 5};
-	const int d[] = {INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
-			INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
-			INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ};
+	static const int hz[] = {188, 98, 42, 20, 10, 5};
+	static const int d[] = {
+		INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
+		INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
+		INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ
+	};
 	int i, h, result;
 	u8 data;