dt-bindings: iio: light: stk33xx: Add proximity-near-level

This allows exporting the value from which userspace should assert an
object is "near".

Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220420112540.91907-2-arnaud.ferraris@collabora.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/light/stk33xx.yaml

@@ -13,6 +13,9 @@ maintainers:
 description: |
   Ambient light and proximity sensor over an i2c interface.
 
+allOf:
+  - $ref: ../common.yaml#
+
 properties:
   compatible:
     enum:
@@ -26,6 +29,8 @@ properties:
   interrupts:
     maxItems: 1
 
+  proximity-near-level: true
+
 required:
   - compatible
   - reg
@@ -44,6 +49,7 @@ examples:
         stk3310@48 {
                 compatible = "sensortek,stk3310";
                 reg = <0x48>;
+                proximity-near-level = <25>;
                 interrupt-parent = <&gpio1>;
                 interrupts = <5 IRQ_TYPE_LEVEL_LOW>;
         };