seco-mx8mm: Allow to specify the VIDIO_PLL1_RATE as define

This is a bit hacky but currently I don't know a better solution.

Though the doc say assigned-clock-parents may not be used to set clock rates
if there are multiple consumers this is used here widely.
( see Documentation/devicetree/bindings/clock/clock-bindings.txt line 164)
To allow to change this in devicetree using this file, this macro is
introduced, using the default value from before as default.

BCS 746-001034

arch/arm64/boot/dts/seconorth/imx8mm.dtsi

@@ -13,6 +13,16 @@
 
 #include "imx8mm-pinfunc.h"
 
+/* Though the doc say assigned-clock-parents may not be used to set clock rates
+   if there are multiple consumers this is used here widely.
+   ( see Documentation/devicetree/bindings/clock/clock-bindings.txt line 164)
+   To allow to change this in devicetree using this file, this macro is
+   introduced, using the default value from before as default.
+*/
+#ifndef VIDEO_PLL1_RATE
+#define VIDEO_PLL1_RATE 594000000
+#endif
+
 / {
 	interrupt-parent = <&gic>;
 	#address-cells = <2>;
@@ -773,7 +783,7 @@ clk: clock-controller@30380000 {
 							<400000000>,
 							<400000000>,
 							<750000000>,
-							<594000000>,
+							<VIDEO_PLL1_RATE>,
 							<393216000>,
 							<361267200>;
 			};
@@ -1175,7 +1185,7 @@ lcdif: lcdif@32e00000 {
 				assigned-clock-parents = <&clk IMX8MM_VIDEO_PLL1_OUT>,
 							 <&clk IMX8MM_SYS_PLL2_1000M>,
 							 <&clk IMX8MM_SYS_PLL1_800M>;
-				assigned-clock-rate = <594000000>, <500000000>, <200000000>;
+				assigned-clock-rate = <VIDEO_PLL1_RATE>, <500000000>, <200000000>;
 				interrupts = <GIC_SPI 5 IRQ_TYPE_LEVEL_HIGH>;
 				lcdif-gpr = <&dispmix_gpr>;
 				resets = <&lcdif_resets>;
@@ -1203,7 +1213,7 @@ mipi_dsi: mipi_dsi@32e10000 {
 						  <&clk IMX8MM_CLK_DSI_PHY_REF>;
 				assigned-clock-parents = <&clk IMX8MM_SYS_PLL1_266M>,
 							 <&clk IMX8MM_VIDEO_PLL1_OUT>;
-				assigned-clock-rates = <266000000>, <594000000>;
+				assigned-clock-rates = <266000000>, <VIDEO_PLL1_RATE>;
 				pref-rate =     <11880>;
 				interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;
 				dsi-gpr = <&dispmix_gpr>;