dts: arm: st: n6: use default values for xspi kernel clock

Use the default kernel clock (HCLK5) for the XSPI instances instead of the
peripheral clock which may not be enabled at all.

Signed-off-by: Guillaume Gautier <[email protected]>

Author: gautierg-st

dts/arm/st/n6/stm32n6.dtsi

@@ -691,7 +691,7 @@
 			interrupts = <170 0>;
 			clock-names = "xspix", "xspi-ker", "xspi-mgr";
 			clocks = <&rcc STM32_CLOCK(AHB5, 5)>,
-				 <&rcc STM32_SRC_CKPER XSPI1_SEL(1)>,
+				 <&rcc STM32_SRC_HCLK5 XSPI1_SEL(0)>,
 				 <&rcc STM32_CLOCK(AHB5, 13)>;
 			#address-cells = <1>;
 			#size-cells = <1>;
@@ -704,7 +704,7 @@
 			interrupts = <171 0>;
 			clock-names = "xspix", "xspi-ker", "xspi-mgr";
 			clocks = <&rcc STM32_CLOCK(AHB5, 12)>,
-				 <&rcc STM32_SRC_CKPER XSPI2_SEL(1)>,
+				 <&rcc STM32_SRC_HCLK5 XSPI2_SEL(0)>,
 				 <&rcc STM32_CLOCK(AHB5, 13)>;
 			#address-cells = <1>;
 			#size-cells = <1>;