resolvconf: make it work

The current resolvconf does not work. Make it work with the
following changes.
1. Install normalize-resolvconf, which is used by resolvconf.
2. Add dependencies: sed, util-linux-flock.
   util-linux-flock is needed by our busybox does not support '-w'
   by default. sed is needed because we want to avoid package
   QA issue complaining sed is needed by no one provides it.
3. Add a patch to replace 'readlink -m' with 'readlink -l'.
   This could avoid the runtime dependency on coreutils. The replacement
   is safe as /etc always exits in OE's system.
4. Remove allarch inheritage. This is because the above RDEPENDS
   change does not allow this any more. test_sstate_allarch_samesigs
   would fail if we don't do this.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit 1b0581fd)
Signed-off-by: Steve Sakoman <steve@sakoman.com>