ARM: dts: ux500: Fix orientation of accelerometer

This adds a mounting matrix to the accelerometer
on the TVK1281618 R3.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/ste-href-tvk1281618-r3.dtsi

@@ -89,6 +89,9 @@ accelerometer@19 {
 					     <19 IRQ_TYPE_EDGE_RISING>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&accel_tvk_mode>;
+				mount-matrix = "0", "-1", "0",
+					       "-1", "0", "0",
+					       "0", "0", "-1";
 			};
 			magnetometer@1e {
 				compatible = "st,lsm303dlm-magn";