ARM: dts: Set brcm,enable-l1ss for CM4

Enable the PCIE L1SS on Compute Module 4. It's possible that this is
also the right thing to do for Pi 4, but it has been working as is
up to now.

Signed-off-by: Phil Elwell <[email protected]>

Author: pelwell

arch/arm/boot/dts/bcm2711-rpi-cm4.dts

@@ -252,6 +252,10 @@
 	/delete-node/ wifi-pwrseq;
 };
 
+&pcie0 {
+       brcm,enable-l1ss;
+};
+
 &mmcnr {
 	pinctrl-names = "default";
 	pinctrl-0 = <&sdio_pins>;