[PATCH] arm64: dts: allwinner: pinephone: Add mount matrix to accelerometer

[Dragan Simic <dsimic@xxxxxxxxxxx>]

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: 91f480d40942 ("arm64: dts: allwinner: Add initial support for Pine64 PinePhone")
Cc: stable@xxxxxxxxxxxxxxx
Helped-by: Ondrej Jirman <megi@xxxxxx>
Helped-by: Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx>
Signed-off-by: Dragan Simic <dsimic@xxxxxxxxxxx>
---

Notes:
    See also the linux-sunxi thread [2] that has led to this patch, which
    provides a rather detailed analysis with additional details and pictures.
    This patch effectively replaces the patch submitted in that thread.
    
    [2] https://lore.kernel.org/linux-sunxi/20240916204521.2033218-1-andrej.skvortzov@xxxxxxxxx/T/#u

 arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
index 6eab61a12cd8..b844759f52c0 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi
@@ -212,6 +212,9 @@ accelerometer@68 {
 		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";
 	};
 };