arm64: dts: qcom: pmi8994: Fix "eternal"->"external" typo in WLED node

The property is named "qcom,external-pfet", as found by
dt_binding_check:

    'qcom,eternal-pfet' does not match any of the regexes

Fixes: 37aa540c ("arm64: dts: qcom: pmi8994: Add WLED node")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-By: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211007213400.258371-11-marijn.suijten@somainline.org

arch/arm64/boot/dts/qcom/pmi8994.dtsi

@@ -42,7 +42,7 @@ pmi8994_wled: wled@d800 {
 			/* Yes, all four strings *have to* be defined or things won't work. */
 			qcom,enabled-strings = <0 1 2 3>;
 			qcom,cabc;
-			qcom,eternal-pfet;
+			qcom,external-pfet;
 			status = "disabled";
 		};
 	};