arm64/dts: fsl-lx2160a: add missing #pinctrl-cells to pinmux node

The pinctrl-single driver requires #pinctrl-cells = <2> for nodes using
pinctrl-single,bit-per-mux mode. Without this property, the driver fails
to probe the pinmux@70010012c node on the LX2160A with error -22, which
cascades into deferred probe failures for I2C, SPI, SD card, and other
peripherals whose pin configuration depends on this pinmux controller.

This affects the SolidRun HoneyComb LX2 and ClearFog CX platforms which
use the kernel DTB. Symptoms include:

  pinctrl-single 70010012c.pinmux: probe with driver pinctrl-single
  failed with error -22

  platform 2140000.mmc: deferred probe pending: wait for supplier
  /soc/pinmux@70010012c/sdhc1-base-sdhc-vsel-pins

Adding the missing property allows the pinmux controller to probe
correctly, restoring I2C bus availability, PCA9547 mux initialisation,
SD card, SPI flash, and fan speed control via the AMC6821 controller.


--- linux-6.18.36.orig/arch/arm64/boot/dts/freescale/fsl-lx2160a.dtsi	2026-06-19 12:44:16.000000000 +0100
+++ linux-6.18.36/arch/arm64/boot/dts/freescale/fsl-lx2160a.dtsi	2026-06-23 11:48:02.771036079 +0100
@@ -1713,6 +1713,7 @@
 			reg = <0x00000007 0x0010012c 0x0 0xc>;
 			#address-cells = <1>;
 			#size-cells = <0>;
+			#pinctrl-cells = <2>;
 			pinctrl-single,bit-per-mux;
 			pinctrl-single,register-width = <32>;
 			pinctrl-single,function-mask = <0x7>;
