[BOARD] Remove screenshot script

no need after moving whole shell cmd to kernel

board/miyoo/main/apps/fbgrab/screenshot.sh

@@ -1,11 +0,0 @@
-#!/bin/sh
-name=/mnt/screenshots/system
-mkdir -p /mnt/screenshots
-if [[ -e $name.png ]] ; then
-    i=1
-    while [[ -e $name-$i.png ]] ; do
-        let i++
-    done
-    name=$name-$i
-fi
-fbgrab "$name".png