docs-rst: get rid of Documentation/sphinx/tmplcvt script

As everything was converted to ReST, we don't need this
script anymore.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/sphinx/tmplcvt

-#!/bin/bash
-#
-# Convert a template file into something like RST
-#
-# fix <function>
-# feed to pandoc
-# fix \_
-# title line?
-#
-set -eu
-
-if [ "$#" != "2" ]; then
-	echo "$0 <docbook file> <rst file>"
-	exit
-fi
-
-DIR=$(dirname $0)
-
-in=$1
-rst=$2
-tmp=$rst.tmp
-
-cp $in $tmp
-sed --in-place -f $DIR/convert_template.sed $tmp
-pandoc -s -S -f docbook -t rst -o $rst $tmp
-sed --in-place -f $DIR/post_convert.sed $rst
-rm $tmp
-echo "book writen to $rst"