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/socketcand/socketcand.hash

@@ -1,3 +1,3 @@
 # Locally computed
 sha256  3c5cc7af4ff707ac344e62d2e37a74b59aeccd14b88e837cc142c52b69d64a39  socketcand-69e2201222f015a1abe7a58ecf61325012cd91b1.tar.gz
-sha256  b32028a4080be38208ee951c6e8afc6f3bfb3d5496559b260ab0dce9472740f6  socketcand.c
+sha256  18bda0db4e3c56cefdb1b9b01b7eada7764c0746f6321378c30d78f5ee81cfee  socketcand.c