Revert "pico-imx7d: enalbe 1.2GHz"

This reverts commit ae7c1d94e1d886525fc0ced61488095114779265.
(cherry picked from commit b3103703bf856559e33bb4038e8c0915bf972f1a)

Change-Id: I1e10cd3cc3a70a101abf2e3b7c393a433ffaf518
diff --git a/arch/arm/boot/dts/imx7d.dtsi b/arch/arm/boot/dts/imx7d.dtsi
index 963bfb1..f97ee1c 100644
--- a/arch/arm/boot/dts/imx7d.dtsi
+++ b/arch/arm/boot/dts/imx7d.dtsi
@@ -53,7 +53,6 @@
 			reg = <0>;
 			operating-points = <
 				/* KHz	uV */
-				1200000 1100000
 				996000	1075000
 				792000	975000
 			>;