ar71xx: base-files: remove the now unneeded 09_fix-seama-header

It was intended as a workaround when jffs2 eof mark was included in the
checksum calculation in seama header.  When qihoo-c301 support was
introduced the board name was not inserted into the case list (because I
was not aware of it's existence), but the issue was fixed by excluding
the jffs2 marker as part of the checksum data

Now we are at it, drop it.

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

target/linux/ar71xx/base-files/etc/uci-defaults/09_fix-seama-header

@@ -1,21 +0,0 @@
-#!/bin/sh
-#
-# Copyright (C) 2013 OpenWrt.org
-#
-
-. /lib/ar71xx.sh
-
-fix_seama_header() {
-	local part=$1
-
-	mtd fixseama $part
-}
-
-board=$(ar71xx_board_name)
-
-case "$board" in
-mynet-n600 | \
-mynet-n750)
-	fix_seama_header kernel
-	;;
-esac