drivers: adc: support Nuvoton numaker series

Add Nuvoton numaker series adc controller, including async read feature.

Signed-off-by: cyliang tw <cyliang@nuvoton.com>

dts/bindings/adc/nuvoton,numaker-adc.yaml

@@ -0,0 +1,32 @@
+# Copyright (c) 2023 Nuvoton Technology Corporation.
+# SPDX-License-Identifier: Apache-2.0
+
+description: Nuvoton, NuMaker ADC controller
+
+compatible: "nuvoton,numaker-adc"
+
+include: [adc-controller.yaml, reset-device.yaml, pinctrl-device.yaml]
+
+properties:
+  reg:
+    required: true
+
+  interrupts:
+    required: true
+
+  resets:
+    required: true
+
+  clocks:
+    required: true
+
+  channels:
+    type: int
+    description: Number of channels
+    required: true
+
+  "#io-channel-cells":
+    const: 1
+
+io-channel-cells:
+  - input