arm64: dts: qcom: sc7180: Rename gic-its node to msi-controller

Running `make dtbs_check` yells:

  arch/arm64/boot/dts/qcom/sc7180-idp.dt.yaml: interrupt-controller@17a00000: gic-its@17a40000: False schema

From "arm,gic-v3.yaml" we can grok that this is explained by the
comment "msi-controller is preferred".  Switch to the preferred name
so that dtbs_check stops yelling.
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Fixes: 90db71e4 ("arm64: dts: sc7180: Add minimal dts/dtsi files for SC7180 soc")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20191212113540.2.Ibad7d3b0bea02957e89047942c61cc6c0aa61715@changeidSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

arch/arm64/boot/dts/qcom/sc7180.dtsi

@@ -1189,7 +1189,7 @@
 			      <0 0x17a60000 0 0x100000>;    /* GICR * 8 */
 			interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
 
-			gic-its@17a40000 {
+			msi-controller@17a40000 {
 				compatible = "arm,gic-v3-its";
 				msi-controller;
 				#msi-cells = <1>;