sunxi: remove unneeded shebang for preinit files

preinit files are sourced and they have no execute bit set, so remove
their shebang.

Signed-off-by: Adrian Schmutzler <[email protected]>

target/linux/sunxi/base-files/lib/preinit/03_b53_hack.sh

@@ -1,5 +1,3 @@
-#!/bin/sh
-
 do_b53_hack() {
 	. /lib/functions.sh
 

target/linux/sunxi/base-files/lib/preinit/79_move_config

@@ -1,4 +1,3 @@
-#!/bin/sh
 # Copyright (C) 2012-2015 OpenWrt.org
 
 move_config() {