screen blank: maintainer should specify in Board whether to disable

Change-Id: Id7dfea1ed9391d5a5f617b72a25fdb74dc235537
diff --git a/gui/libguitwrp_defaults.go b/gui/libguitwrp_defaults.go
index 00ef028..9e8fd0b 100644
--- a/gui/libguitwrp_defaults.go
+++ b/gui/libguitwrp_defaults.go
@@ -227,10 +227,6 @@
 		cflags = append(cflags, "-DAB_OTA_UPDATER=1")
 	}
 
-	if getMakeVars(ctx, "TW_SCREEN_BLANK_ON_BOOT") == "true" {
-		cflags = append(cflags, "-DTW_NO_SCREEN_BLANK")
-	}
-
 	return cflags
 }