arm64: dts: qcom: msm8996: drop unused slimbus dmas

Bindings document only two DMA channels.  Linux driver also does not use
remaining rx2/tx2.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220928152027.489543-7-krzysztof.kozlowski@linaro.org

arch/arm64/boot/dts/qcom/msm8996.dtsi

@@ -3331,9 +3331,8 @@ slim_msm: slim@91c0000 {
 			compatible = "qcom,slim-ngd-v1.5.0";
 			reg = <0x091c0000 0x2C000>;
 			interrupts = <0 163 IRQ_TYPE_LEVEL_HIGH>;
-			dmas = <&slimbam 3>, <&slimbam 4>,
-				<&slimbam 5>, <&slimbam 6>;
-			dma-names = "rx", "tx", "tx2", "rx2";
+			dmas = <&slimbam 3>, <&slimbam 4>;
+			dma-names = "rx", "tx";
 			#address-cells = <1>;
 			#size-cells = <0>;
 			ngd@1 {