iio: st_accel: fix interrupt handling on LIS3LV02

This accelerometer accidentally either emits a DRDY signal or an
IRQ signal. Accidentally I activated the IRQ signal as I thought
it was analogous to the interrupt generator on other ST
accelerometers. This was wrong. After this patch generic_buffer
gives a nice stream of accelerometer readings.

Fixes: 3acddf74f807778f "iio: st-sensors: add support for lis3lv02d accelerometer"
Cc: Denis CIOCCA <denis.ciocca@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/accel/st_accel_core.c

@@ -149,8 +149,6 @@
 #define ST_ACCEL_4_BDU_MASK			0x40
 #define ST_ACCEL_4_DRDY_IRQ_ADDR		0x21
 #define ST_ACCEL_4_DRDY_IRQ_INT1_MASK		0x04
-#define ST_ACCEL_4_IG1_EN_ADDR			0x21
-#define ST_ACCEL_4_IG1_EN_MASK			0x08
 #define ST_ACCEL_4_MULTIREAD_BIT		true
 
 /* CUSTOM VALUES FOR SENSOR 5 */
@@ -489,10 +487,6 @@ static const struct st_sensor_settings st_accel_sensors_settings[] = {
 		.drdy_irq = {
 			.addr = ST_ACCEL_4_DRDY_IRQ_ADDR,
 			.mask_int1 = ST_ACCEL_4_DRDY_IRQ_INT1_MASK,
-			.ig1 = {
-				.en_addr = ST_ACCEL_4_IG1_EN_ADDR,
-				.en_mask = ST_ACCEL_4_IG1_EN_MASK,
-			},
 		},
 		.multi_read_bit = ST_ACCEL_4_MULTIREAD_BIT,
 		.bootime = 2, /* guess */