iio: lps331ap: Modify in_temp_scale calculation way

This patch modifies the way how the in_temp_scale output value is
calculated. With this implementation it is more clear how the value
is obtained.
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/pressure/st_pressure_core.c

@@ -31,6 +31,9 @@
 #define ST_PRESS_LSB_PER_MBAR			4096UL
 #define ST_PRESS_KPASCAL_NANO_SCALE		(100000000UL / \
 						 ST_PRESS_LSB_PER_MBAR)
+#define ST_PRESS_LSB_PER_CELSIUS		480UL
+#define ST_PRESS_CELSIUS_NANO_SCALE		(1000000000UL / \
+						 ST_PRESS_LSB_PER_CELSIUS)
 #define ST_PRESS_NUMBER_DATA_CHANNELS		1
 
 /* DEFAULT VALUE FOR SENSORS */
@@ -53,8 +56,8 @@
 #define ST_PRESS_1_FS_ADDR			0x23
 #define ST_PRESS_1_FS_MASK			0x30
 #define ST_PRESS_1_FS_AVL_1260_VAL		0x00
-#define ST_PRESS_1_FS_AVL_TEMP_GAIN		2083000
 #define ST_PRESS_1_FS_AVL_1260_GAIN		ST_PRESS_KPASCAL_NANO_SCALE
+#define ST_PRESS_1_FS_AVL_TEMP_GAIN		ST_PRESS_CELSIUS_NANO_SCALE
 #define ST_PRESS_1_BDU_ADDR			0x20
 #define ST_PRESS_1_BDU_MASK			0x04
 #define ST_PRESS_1_DRDY_IRQ_ADDR		0x22