ARM: dts: imx53-qsb: disable 1.2GHz OPP

BugLink: https://bugs.launchpad.net/bugs/1810807

[ Upstream commit eea96566 ]

The maximum CPU frequency for the i.MX53 QSB is 1GHz, so disable the
1.2GHz OPP. This makes the board work again with configs that have
cpufreq enabled like imx_v6_v7_defconfig on which the board stopped
working with the addition of cpufreq-dt support.

Fixes: 791f4166 ("ARM: dts: imx53: add cpufreq-dt support")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/arm/boot/dts/imx53-qsb-common.dtsi

@@ -130,6 +130,17 @@ sound {
 	};
 };
 
+&cpu0 {
+	/* CPU rated to 1GHz, not 1.2GHz as per the default settings */
+	operating-points = <
+		/* kHz   uV */
+		166666  850000
+		400000  900000
+		800000  1050000
+		1000000 1200000
+	>;
+};
+
 &esdhc1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_esdhc1>;