arm64: dts: allwinner: pinephone: Add mount matrix to accelerometer

The way InvenSense MPU-6050 accelerometer is mounted on the user-facing side
of the Pine64 PinePhone mainboard, which makes it rotated 90 degrees counter-
clockwise, [1] requires the accelerometer's x- and y-axis to be swapped, and
the direction of the accelerometer's y-axis to be inverted.

Rectify this by adding a mount-matrix to the accelerometer definition in the
Pine64 PinePhone dtsi file.

[1] https://files.pine64.org/doc/PinePhone/PinePhone%20mainboard%20bottom%20placement%20v1.1%2020191031.pdf

Fixes: 91f480d409 ("arm64: dts: allwinner: Add initial support for Pine64 PinePhone")
Cc: stable@vger.kernel.org
Suggested-by: Ondrej Jirman <megi@xff.cz>
Suggested-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Reviewed-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Link: https://patch.msgid.link/129f0c754d071cca1db5d207d9d4a7bd9831dff7.1726773282.git.dsimic@manjaro.org
[wens@csie.org: Replaced Helped-by with Suggested-by]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi

@@ -230,6 +230,9 @@
 		interrupts = <7 5 IRQ_TYPE_EDGE_RISING>; /* PH5 */
 		vdd-supply = <&reg_dldo1>;
 		vddio-supply = <&reg_dldo1>;
+		mount-matrix = "0", "1", "0",
+			       "-1", "0", "0",
+			       "0", "0", "1";
 	};
 };