dt-bindings: arm: bcm: Convert BCM2835 firmware binding to YAML

Convert the Raspberry Pi BCM2835 firmware binding document to YAML.
Verified with dt_binding_check and dtbs_check.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/5bc0b9be8544b07300fccab4d4f26e5e5d8e62b2.1592210452.git-series.maxime@cerno.techSigned-off-by: Stephen Boyd <sboyd@kernel.org>

Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.txt

-Raspberry Pi VideoCore firmware driver
-
-Required properties:
-
-- compatible:		Should be "raspberrypi,bcm2835-firmware"
-- mboxes:		Phandle to the firmware device's Mailbox.
-			  (See: ../mailbox/mailbox.txt for more information)
-
-Example:
-
-firmware {
-	compatible = "raspberrypi,bcm2835-firmware";
-	mboxes = <&mailbox>;
-};

Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml

+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/bcm/raspberrypi,bcm2835-firmware.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Raspberry Pi VideoCore firmware driver
+
+maintainers:
+  - Eric Anholt <eric@anholt.net>
+  - Stefan Wahren <wahrenst@gmx.net>
+
+properties:
+  compatible:
+    items:
+      - const: raspberrypi,bcm2835-firmware
+      - const: simple-bus
+
+  mboxes:
+    $ref: '/schemas/types.yaml#/definitions/phandle'
+    description: |
+      Phandle to the firmware device's Mailbox.
+      (See: ../mailbox/mailbox.txt for more information)
+
+required:
+  - compatible
+  - mboxes
+
+examples:
+  - |
+    firmware {
+        compatible = "raspberrypi,bcm2835-firmware", "simple-bus";
+        mboxes = <&mailbox>;
+    };
+...