realtek: ZyXEL: spell as done by manufacturer

ZyXEL spells its own name all uppercase with just the Y lowercase. Adapt
the realtek target to follow this (other OpenWrt targets already do so).

Signed-off-by: Stijn Segers <[email protected]>

target/linux/realtek/dts/rtl8380_zyxel_gs1900-10hp.dts

@@ -7,7 +7,7 @@
 
 / {
 	compatible = "zyxel,gs1900-10hp", "realtek,rtl838x-soc";
-	model = "Zyxel GS1900-10HP Switch";
+	model = "ZyXEL GS1900-10HP Switch";
 
 	aliases {
 		led-boot = &led_sys;

target/linux/realtek/image/Makefile

@@ -68,7 +68,7 @@ TARGET_DEVICES += netgear_gs110tpp-v1
 define Device/zyxel_gs1900-10hp
   SOC := rtl8380
   IMAGE_SIZE := 6976k
-  DEVICE_VENDOR := Zyxel
+  DEVICE_VENDOR := ZyXEL
   DEVICE_MODEL := GS1900-10HP
 endef
 TARGET_DEVICES += zyxel_gs1900-10hp