dpkg: add perl to RDEPENDS

perl scripts:
packages-split/dpkg/usr/bin/dpkg-parsechangelog:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-mergechangelogs:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-architecture:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-vendor:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-shlibdeps:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-scanpackages:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-buildpackage:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-genchanges:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-gensymbols:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-distaddfile:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-buildflags:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-checkbuilddeps:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-gencontrol:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-scansources:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-source:#!/usr/bin/perl
packages-split/dpkg/usr/bin/dpkg-name:#!/usr/bin/perl
packages-split/dpkg/usr/lib/dpkg/parsechangelog/debian:#!/usr/bin/perl

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>