skl mainboards/dt: Move SsicPortEnable setting into XHCI device scope

Change-Id: I64ffba35303c1291f56ae6a038325a7482158ad3
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83189
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Marvin Evers <marvin.n.evers@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/intel/saddlebrook/devicetree.cb b/src/mainboard/intel/saddlebrook/devicetree.cb
index 2f5058d..c92377a 100644
--- a/src/mainboard/intel/saddlebrook/devicetree.cb
+++ b/src/mainboard/intel/saddlebrook/devicetree.cb
@@ -120,10 +120,6 @@
 	register "PcieRpClkReqNumber[5]" = "0"
 	register "PcieRpClkReqNumber[12]" = "1"
 
-	# USB related
-	register "SsicPortEnable" = "1"
-
-
 	register "i2c_voltage[4]" = "I2C_VOLTAGE_1V8"  # I2C4 is 1.8V
 
 	# Must leave UART0 enabled or SD/eMMC will not work as PCI
@@ -156,6 +152,8 @@
 	device domain 0 on
 		device ref igpu		on end
 		device ref south_xhci	on
+			register "SsicPortEnable" = "1"
+
 			register "usb2_ports" = "{
 				[0] = USB2_PORT_MID(OC_SKIP),	/* OTG */
 				[1] = USB2_PORT_MID(OC3),	/* Touch Pad */