Bump buildroot to 2020.11-rc1 (#985)

* Update buildroot-patches for 2020.11-rc1 buildroot

* Update buildroot to 2020.11-rc1

Signed-off-by: Stefan Agner <stefan@agner.ch>

* Don't rely on sfdisk --list-free output

The --list-free (-F) argument does not allow machine readable mode. And
it seems that the output format changes over time (different spacing,
using size postfixes instead of raw blocks).

Use sfdisk json output and calculate free partition space ourselfs. This
works for 2.35 and 2.36 and is more robust since we rely on output which
is meant for scripts to parse.

* Migrate defconfigs for Buildroot 2020.11-rc1

In particular, rename BR2_TARGET_UBOOT_BOOT_SCRIPT(_SOURCE) to
BR2_PACKAGE_HOST_UBOOT_TOOLS_BOOT_SCRIPT(_SOURCE).

* Rebase/remove systemd patches for systemd 246

* Drop apparmor/libapparmor from buildroot-external

* hassos-persists: use /run as directory for lockfiles

The U-Boot tools use /var/lock by default which is not created any more
by systemd by default (it is under tmpfiles legacy.conf, which we no
longer install).

* Disable systemd-update-done.service

The service is not suited for pure read-only systems. In particular the
service needs to be able to write a file in /etc and /var. Remove the
service. Note: This is a static service and cannot be removed using
systemd-preset.

* Disable apparmor.service for now

The service loads all default profiles. Some might actually cause
problems. E.g. the profile for ping seems not to match our setup for
/etc/resolv.conf:
[85503.634653] audit: type=1400 audit(1605286002.684:236): apparmor="DENIED" operation="open" profile="ping" name="/run/resolv.conf" pid=27585 comm="ping" requested_mask="r" denied_mask="r" fsuid=0 ouid=0

buildroot/package/iputils/iputils.hash

@@ -1,5 +1,5 @@
-# https://github.com/iputils/iputils/releases/download/s20190709/sha256sum.asc
-sha256 a15720dd741d7538dd2645f9f516d193636ae4300ff7dbc8bfca757bf166490a  iputils-20190709.tar.gz
+# https://github.com/iputils/iputils/releases/download/s20200821/sha256sum.asc
+sha256 f265da0d02dd2259efd8c57a9c2e0c8bb3361abb14639fcffb26707be5783a5b  iputils-20200821.tar.gz
 # Locally computed
 sha256 b8ea785d12fa6a44916601104dd746216957e93f13a26d3eb858b3b5a4ad66ab  LICENSE
 sha256 9acc4bc871a4742550158e3696dcb381953172ef808d04ca248184f9f6322712  Documentation/LICENSE.BSD3