devicetrees: Remove trailing backslash from multiline values

It's not needed to put a backslash at the end of a line for quoted
multiline values. Thus, remove it.

Change-Id: I1b83d53598ba2adeed853a96d6c2c1a21f01a9f7
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78576
Reviewed-by: Erik van den Bogaert <ebogaert@eltan.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/mainboard/intel/kunimitsu/devicetree.cb b/src/mainboard/intel/kunimitsu/devicetree.cb
index bc068c6..03ace20 100644
--- a/src/mainboard/intel/kunimitsu/devicetree.cb
+++ b/src/mainboard/intel/kunimitsu/devicetree.cb
@@ -132,18 +132,18 @@
 	register "i2c_voltage[4]" = "I2C_VOLTAGE_1V8"  # I2C4 is 1.8V
 
 	# Must leave UART0 enabled or SD/eMMC will not work as PCI
-	register "SerialIoDevMode" = "{ \
-		[PchSerialIoIndexI2C0]  = PchSerialIoPci, \
-		[PchSerialIoIndexI2C1]  = PchSerialIoPci, \
-		[PchSerialIoIndexI2C2]  = PchSerialIoDisabled, \
-		[PchSerialIoIndexI2C3]  = PchSerialIoDisabled, \
-		[PchSerialIoIndexI2C4]  = PchSerialIoPci, \
-		[PchSerialIoIndexI2C5]  = PchSerialIoDisabled, \
-		[PchSerialIoIndexSpi0]  = PchSerialIoDisabled, \
-		[PchSerialIoIndexSpi1]  = PchSerialIoDisabled, \
-		[PchSerialIoIndexUart0] = PchSerialIoPci, \
-		[PchSerialIoIndexUart1] = PchSerialIoDisabled, \
-		[PchSerialIoIndexUart2] = PchSerialIoSkipInit, \
+	register "SerialIoDevMode" = "{
+		[PchSerialIoIndexI2C0]  = PchSerialIoPci,
+		[PchSerialIoIndexI2C1]  = PchSerialIoPci,
+		[PchSerialIoIndexI2C2]  = PchSerialIoDisabled,
+		[PchSerialIoIndexI2C3]  = PchSerialIoDisabled,
+		[PchSerialIoIndexI2C4]  = PchSerialIoPci,
+		[PchSerialIoIndexI2C5]  = PchSerialIoDisabled,
+		[PchSerialIoIndexSpi0]  = PchSerialIoDisabled,
+		[PchSerialIoIndexSpi1]  = PchSerialIoDisabled,
+		[PchSerialIoIndexUart0] = PchSerialIoPci,
+		[PchSerialIoIndexUart1] = PchSerialIoDisabled,
+		[PchSerialIoIndexUart2] = PchSerialIoSkipInit,
 	}"
 
 	# PL2 override 25W