zen/zenxfi: implement lcd standby

Change-Id: I5960221d45490c469ffd2a481d447185aba70e56
diff --git a/firmware/target/arm/imx233/creative-zen/lcd-zen.c b/firmware/target/arm/imx233/creative-zen/lcd-zen.c
index 8390d19..fd7d3e0 100644
--- a/firmware/target/arm/imx233/creative-zen/lcd-zen.c
+++ b/firmware/target/arm/imx233/creative-zen/lcd-zen.c
@@ -321,6 +321,10 @@
         return;
 
     lcd_on = enable;
+    if(lcd_on)
+        lcd_standby_out_seq();
+    else
+        lcd_standby_in_seq();
 }
 #endif