dts: bindings: gpio: add binding for GPIOs in ADS114S08

Add binding for the GPIOs within the ADC ADS114S08.

Signed-off-by: Benedikt Schmidt <benedikt.schmidt@embedded-solutions.at>

dts/bindings/adc/ti,ads114s08.yaml

@@ -7,6 +7,8 @@ compatible: "ti,ads114s08"
 
 include: [adc-controller.yaml, spi-device.yaml]
 
+bus: ads114s0x
+
 properties:
   "#io-channel-cells":
     const: 1

dts/bindings/gpio/ti,ads114s0x-gpio.yaml

@@ -0,0 +1,27 @@
+#
+# Copyright (c) 2022 SILA Embedded Solutions GmbH
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+description: TI ADS114S0x GPIO controller binding
+
+compatible: "ti,ads114s0x-gpio"
+
+include: [gpio-controller.yaml, base.yaml]
+
+on-bus: ads114s0x
+
+properties:
+  "#gpio-cells":
+    const: 2
+
+  ngpios:
+    type: int
+    required: true
+    const: 4
+    description: Number of gpios supported
+
+gpio-cells:
+  - pin
+  - flags