brcm47xx: Fix sysupgrade with E1200v1

Entry was missing for some reason.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

target/linux/brcm47xx/base-files/lib/upgrade/platform.sh

@@ -34,6 +34,7 @@ platform_expected_image() {
 		"Linksys E1000 V1")	echo "cybertan E100"; return;;
 		"Linksys E1000 V2")	echo "cybertan E100"; return;;
 		"Linksys E1000 V2.1")	echo "cybertan E100"; return;;
+		"Linksys E1200 V1")	echo "cybetran E120"; return;;
 		"Linksys E1200 V2")	echo "cybertan E122"; return;;
 		"Linksys E2000 V1")	echo "cybertan 32XN"; return;;
 		"Linksys E3000 V1")	echo "cybertan 61XN"; return;;