iio: gyro: st_gyro: add SPI-3wire support to st_gyro framework

Add SPI Serial Interface Mode (SIM) register information
to STM gyroscope framework

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
diff --git a/drivers/iio/gyro/st_gyro_core.c b/drivers/iio/gyro/st_gyro_core.c
index 46991f7..b31064b 100644
--- a/drivers/iio/gyro/st_gyro_core.c
+++ b/drivers/iio/gyro/st_gyro_core.c
@@ -125,6 +125,10 @@ static const struct st_sensor_settings st_gyro_sensors_settings[] = {
 				.mask = 0x07,
 			},
 		},
+		.sim = {
+			.addr = 0x23,
+			.value = BIT(0),
+		},
 		.multi_read_bit = true,
 		.bootime = 2,
 	},
@@ -200,6 +204,10 @@ static const struct st_sensor_settings st_gyro_sensors_settings[] = {
 				.mask = 0x07,
 			},
 		},
+		.sim = {
+			.addr = 0x23,
+			.value = BIT(0),
+		},
 		.multi_read_bit = true,
 		.bootime = 2,
 	},
@@ -270,6 +278,10 @@ static const struct st_sensor_settings st_gyro_sensors_settings[] = {
 				.mask = 0x07,
 			},
 		},
+		.sim = {
+			.addr = 0x23,
+			.value = BIT(0),
+		},
 		.multi_read_bit = true,
 		.bootime = 2,
 	},