Migrate to libyang2

Also update buildroot to latest master:
- the sdbus-cpp version bump patch has been removed, because upstream
  now bumped it to an even newer version

- Fix RAUC not able to start a service
(https://github.com/buildroot/buildroot/commit/72308ab9a32de6e8b4b23e42f115ed5ee87e5f33)

Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/netconf-cli/+/4539
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/netconf-cli/+/4539
Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/rousette/+/5391
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/rousette/+/5391
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/cla-sysrepo/+/5292
Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/velia/+/5237
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/velia/+/5237
Change-Id: I6edc19f35accfd41a4b32f7b396981d470e0c07b
diff --git a/board/czechlight/common/patches/systemd/random-seed.patch b/board/czechlight/common/patches/systemd/random-seed.patch
index e79c9af..dac46cf 100644
--- a/board/czechlight/common/patches/systemd/random-seed.patch
+++ b/board/czechlight/common/patches/systemd/random-seed.patch
@@ -24,13 +24,13 @@
 --- a/meson.build
 +++ b/meson.build
 @@ -155,7 +155,7 @@ bootlibdir = join_paths(prefixdir, 'lib/systemd/boot/efi')
- testsdir = join_paths(prefixdir, 'lib/systemd/tests')
- systemdstatedir = join_paths(localstatedir, 'lib/systemd')
- catalogstatedir = join_paths(systemdstatedir, 'catalog')
--randomseeddir = join_paths(localstatedir, 'lib/systemd')
+ testsdir = prefixdir / 'lib/systemd/tests'
+ systemdstatedir = localstatedir / 'lib/systemd'
+ catalogstatedir = systemdstatedir / 'catalog'
+-randomseeddir = localstatedir / 'lib/systemd'
 +randomseeddir = '/cfg/random-seed'
- profiledir = join_paths(rootlibexecdir, 'portable', 'profile')
- ntpservicelistdir = join_paths(rootprefixdir, 'lib/systemd/ntp-units.d')
+ profiledir = rootlibexecdir / 'portable' / 'profile'
+ ntpservicelistdir = rootprefixdir / 'lib/systemd/ntp-units.d'
  
 -- 
 2.21.0