iio: light: ltr501 Fix interchanged als/ps register field

The register mapping for the IIO driver for the Liteon Light and Proximity
sensor LTR501 interrupt mode is interchanged (ALS/PS).
There is a register called INTERRUPT register (address 0x8F)
Bit 0 represents PS measurement trigger.
Bit 1 represents ALS measurement trigger.
This two bit fields are interchanged within the driver.
see datasheet page 24:
http://optoelectronics.liteon.com/upload/download/DS86-2012-0006/S_110_LTR-501ALS-01_PrelimDS_ver1%5B1%5D.pdf

Signed-off-by: Franziska Naepelt <franziska.naepelt@idt.com>
Fixes: 7ac702b3144b6 ("iio: ltr501: Add interrupt support")
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/light/ltr501.c

@@ -74,9 +74,9 @@ static const int int_time_mapping[] = {100000, 50000, 200000, 400000};
 static const struct reg_field reg_field_it =
 				REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
 static const struct reg_field reg_field_als_intr =
-				REG_FIELD(LTR501_INTR, 0, 0);
-static const struct reg_field reg_field_ps_intr =
 				REG_FIELD(LTR501_INTR, 1, 1);
+static const struct reg_field reg_field_ps_intr =
+				REG_FIELD(LTR501_INTR, 0, 0);
 static const struct reg_field reg_field_als_rate =
 				REG_FIELD(LTR501_ALS_MEAS_RATE, 0, 2);
 static const struct reg_field reg_field_ps_rate =