u-boot: fix typo in boot.scr

fix serial console output on RPi3 B+ at aarch64

Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>

config/rootfiles/core/127/filelists/files

@@ -1,3 +1,5 @@
+boot/boot.cmd
+boot/boot.scr
 etc/system-release
 etc/issue
 srv/web/ipfire/cgi-bin/credits.cgi

config/u-boot/boot.cmd

@@ -39,7 +39,7 @@ if test "${SERIAL-CONSOLE}" = "ON"; then
 	if test ${console} = ""; then
 		if test "${board}" = "rpi"; then
 			if test ${cpu} = "armv8"; then
-				if test "${fdtfile}" = "boradcom/bcm2837-rpi-3-b-plus.dtb"; then
+				if test "${fdtfile}" = "broadcom/bcm2837-rpi-3-b-plus.dtb"; then
 					setenv console ttyS1,115200n8;
 				else
 					if test "${fdtfile}" = "broadcom/bcm2837-rpi-3-b.dtb"; then