Added sl_enable_rgb_led in inside if-else of soc board condition

Author: bhmanda-silabs

third_party/silabs/silabs_board.gni

@@ -75,12 +75,11 @@ if (silabs_board == "") {
 
 assert(silabs_board != "", "silabs_board must be specified")
 
-if (silabs_board == "BRD2605A") {
-  sl_enable_rgb_led = true
-}
-
 # Si917 WIFI board ----------
 if (silabs_board == "BRD4338A" || silabs_board == "BRD2605A") {
+  if (silabs_board == "BRD2605A") {
+    sl_enable_rgb_led = true
+  }
   silabs_family = "SiWx917-common"
   silabs_mcu = "SiWG917M111MGTBA"
   wifi_soc = true