dts: bindings: reset: added bindings for Raspberry Pi Pico

added reset bindings for Raspberry Pi Pico board

Signed-off-by: Andrei-Edward Popa <andrei.popa105@yahoo.com>

dts/bindings/reset/raspberrypi,pico-reset.yaml

@@ -0,0 +1,25 @@
+# Copyright (c) 2022 Andrei-Edward Popa
+# SPDX-License-Identifier: Apache-2.0
+
+description: Raspberry Pi Pico Reset Controller
+
+compatible: "raspberrypi,pico-reset"
+
+include: [base.yaml, reset-controller.yaml]
+
+properties:
+    reg:
+      required: true
+    reg-width:
+      type: int
+      required: false
+      description: The width of the reset registers in bytes. Default is 4 bytes.
+    active-low:
+      type: int
+      required: false
+      description: Set if reset is active low. Default is 0, which means active-high.
+    "#reset-cells":
+      const: 1
+
+reset-cells:
+- id