ARM: dts: exynos: use generic name for max77693 motor in Midas

Use a generic name for the max77693 motor driver in Exynos4412 Midas
boards to align with Devicetree specification naming convention.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm/boot/dts/exynos4412-midas.dtsi

···
 				};
 			};
 
-			max77693_haptic {
+			motor-driver {
 				compatible = "maxim,max77693-haptic";
 				haptic-supply = <&ldo26_reg>;
 				pwms = <&pwm 0 38022 0>;