iio: max44000: correct value in illuminance_integration_time_available

According to the datasheet, the shortest available integration time for
ALS ADC conversion is 1.5625ms but illuminance_integration_time_available
sysfs file shows wrong value.

Cc: Crestez Dan Leonard <[e-mail]>
Cc: Jonathan Cameron <[e-mail]>
Cc: Hartmut Knaack <[e-mail]>
Cc: Lars-Peter Clausen <[e-mail]>
Cc: Peter Meerwald-Stadler <[e-mail]>
Signed-off-by: Akinobu Mita <[e-mail]>
Fixes: d5d8f49b6 ("max44000: Expose ambient sensor scaling")
Cc: <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/light/max44000.c

···
 	"0.100 "
 	"0.025 "
 	"0.00625 "
-	"0.001625";
+	"0.0015625";
 
 /* Available scales (internal to ulux) with pretty manual alignment: */
 static const int max44000_scale_avail_ulux_array[] = {