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/package/czechlight-cfg-fs/czechlight-cfg-fs.mk b/package/czechlight-cfg-fs/czechlight-cfg-fs.mk
index 60f4785..bf000bd 100644
--- a/package/czechlight-cfg-fs/czechlight-cfg-fs.mk
+++ b/package/czechlight-cfg-fs/czechlight-cfg-fs.mk
@@ -15,7 +15,7 @@
 define CZECHLIGHT_CFG_FS_BUILD_CMDS
 	$(TARGET_CC) $(CZECHLIGHT_CFG_FS_PKGDIR)/czechlight-random-seed.c -o $(@D)/czechlight-random-seed
 
-	$(HOST_DIR)/usr/bin/yanglint -t config --strict \
+	$(HOST_DIR)/usr/bin/yanglint -t config \
 		$(TARGET_DIR)/usr/share/yang/modules/netopeer2/ietf-netconf-acm@2018-02-14.yang \
 		$(BR2_EXTERNAL_CZECHLIGHT_PATH)/package/czechlight-cfg-fs/nacm.json
 endef