arm64: dts: imx8mp: Update GPIO M to CLKOUT1 on DH electronics i.MX8M Plus DHCOM and PDK2

The GPIO M SoM pin is connected to CLKOUT1, while CLKOUT2 is used as a supply
for TC9595 bridge chip clock. Update the comment. No functional change.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp-dhcom-pdk2.dts

@@ -173,7 +173,7 @@ &iomuxc {
 	/*
 	 * GPIO_A,B,C,D are connected to buttons.
 	 * GPIO_E,F,H,I are connected to LEDs.
-	 * GPIO_M is connected to CLKOUT2.
+	 * GPIO_M is connected to CLKOUT1.
 	 */
 	pinctrl-0 = <&pinctrl_hog_base
 		     &pinctrl_dhcom_g &pinctrl_dhcom_j

arch/arm64/boot/dts/freescale/imx8mp-dhcom-som.dtsi

@@ -547,7 +547,7 @@ &pinctrl_dhcom_a &pinctrl_dhcom_b &pinctrl_dhcom_c
 		     &pinctrl_dhcom_d &pinctrl_dhcom_e &pinctrl_dhcom_f
 		     &pinctrl_dhcom_g &pinctrl_dhcom_h &pinctrl_dhcom_i
 		     &pinctrl_dhcom_j &pinctrl_dhcom_k &pinctrl_dhcom_l
-		     /* GPIO_M is connected to CLKOUT2 */
+		     /* GPIO_M is connected to CLKOUT1 */
 		     &pinctrl_dhcom_int>;
 	pinctrl-names = "default";