dt-bindings: pinctrl: oxnas,pinctrl: remove obsolete bindings

Due to lack of maintenance and stall of development for a few years now,
and since no new features will ever be added upstream, remove the
OX810 and OX820 pinctrl bindings.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230814-topic-oxnas-upstream-remove-v3-2-04a0c5cdda52@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/oxnas,pinctrl.txt

@@ -1,56 +0,0 @@
-* Oxford Semiconductor OXNAS SoC Family Pin Controller
-
-Please refer to pinctrl-bindings.txt, ../gpio/gpio.txt, and
-../interrupt-controller/interrupts.txt for generic information regarding
-pin controller, GPIO, and interrupt bindings.
-
-OXNAS 'pin configuration node' is a node of a group of pins which can be
-used for a specific device or function. This node represents configurations of
-pins, optional function, and optional mux related configuration.
-
-Required properties for pin controller node:
- - compatible: "oxsemi,ox810se-pinctrl" or "oxsemi,ox820-pinctrl"
- - oxsemi,sys-ctrl: a phandle to the system controller syscon node
-
-Required properties for pin configuration sub-nodes:
- - pins: List of pins to which the configuration applies.
-
-Optional properties for pin configuration sub-nodes:
-----------------------------------------------------
- - function: Mux function for the specified pins.
- - bias-pull-up: Enable weak pull-up.
-
-Example:
-
-pinctrl: pinctrl {
-	compatible = "oxsemi,ox810se-pinctrl";
-
-	/* Regmap for sys registers */
-	oxsemi,sys-ctrl = <&sys>;
-
-	pinctrl_uart2: pinctrl_uart2 {
-		uart2a {
-			pins = "gpio31";
-			function = "fct3";
-		};
-		uart2b {
-			pins = "gpio32";
-			function = "fct3";
-		};
-	};
-};
-
-uart2: serial@900000 {
-	compatible = "ns16550a";
-	reg = <0x900000 0x100000>;
-	clocks = <&sysclk>;
-	interrupts = <29>;
-	reg-shift = <0>;
-	fifo-size = <16>;
-	reg-io-width = <1>;
-	current-speed = <115200>;
-	no-loopback-test;
-	resets = <&reset 22>;
-	pinctrl-names = "default";
-	pinctrl-0 = <&pinctrl_uart2>;
-};